He then posted these two comments:
I thought I had nothing to say to twitter but there are at least 500 people carrying light. Don't ask me why because I don't know.and
I think its a chinese tradition. I guess its for good luck. I take the photo and bring good luck to the whole world who is on twitter
So I thought, being hugely curious, that I would see what I could find out.
Firstly I found this really interesting article on the traditions and associations of food culture in farming practices.
TRADITIONAL FARMING VIEWS IN CHINESE DIETARY CULTURE
(Institute of Ethnological Research, Yunnan Academy of Social Sciences, Kunming)
(Kaogu 1997. translated by Jiwu Wang; ed. by B. Gordon)
A close relationship exists between dietary culture and traditional agriculture. On the one hand, the wide variety of agricultural branches and intensive and meticulous farming technology provide plentiful and varied food. In fact, agriculture is the material base on which humans rely. On the other hand, dietary culture employs many concepts related to traditional agriculture, influencing human behavior and giving an inner impulse on agricultural activities. Traditional farming views in Chinese dietary culture include a wish for a good crop, crop protection from natural disasters and the value of hard work. By studying traditional farming views in dietary culture, people obtain a deeper understanding of traditional agriculture.1
In traditional Chinese society, wishing "a bumper grain crop" and "flourishing domestic animals" have been used by most farmers for a long time because these represent the so-called comfortable life. Here, "a bumper grain crop" implies that farmers have plentiful food to give favorable conditions to solve basic living problems. And "flourishing domestic animals" means livestock growth bringing more meat to people. The symbolic meanings of these two phrases are improved living standards and increased wealth, to which all aspire. The desire for a comfortable life, to which all farmers look, is a product of traditional agriculture. It typically reflects their economic concept of agriculture and the important role of agriculture in social life; in fact, their life-time goal. To achieve their ideal of "a bumper grain crop" and "flourishing domestic animals", most farmers work really hard. Moreover, they also perform specific rituals and eat symbolic food to express their wish for a good crop. Symbolically meaningful food is made differently by various ethnic groups; e.g.s, the Han's porridge with beans, nuts and dried fruit, last year's rice, steamed buns, rice buns and noodles, the Kearan's five-grain dish, the Man's steamed buns and steamed sorghum, the Dongxiang's meat porridge, steamed buns, the Kirghiz's Keque dish, the Tu's steamed wheat, the Tujia's mixed vegetable dish, the Naxi's porridge, the Hani's yellow rice and red eggs, the Yao's bird rice, the Zang and Keba's roasted barley, the Maona, Buyi and Yaolao's five-color rice, etc. Beside these symbolic foods, some rituals are prayers for crops, the most typical, eating new rice before harvest. This activity is popular in many agricultural regions and symbolizes a future "bumper grain crop".
Among the so-called five cereals (wugu - rice, two kinds of millet, wheat, beans), the most important is rice, the basic food of south China. Here, people invest much time and material in seed-selection, ploughing, weeding, sowing , irrigating, harvesting, processing, storing, etc. By expending all their energy in growing rice, they hope it yields a good crop because that is their measure of next year's quality of life. As many food customs symbolize wishes for a bumper crop in rice cultures, dietary symbols occur throughout rice growing. Before a farmer in Wuyi region of Zhejiang sows rice, he must eat as much food as he can; its symbolism being future rice growing depends on how much the person has eaten on sowing day. People believe when a satiated person sows rice, the rice will grow correspondingly. In other regions, symbolic food may be steamed rice buns and eggs, which imply strong fast-growing seed rice. On the first day of transplanting, Yiwu people often eat bamboo roots to express their wish that rice will grow as fast as bamboo. Yongkang people often eat zongzi (rice bun wrapped in bamboo leaves) and rice cakes. Zongzi implies all seeds will sprout and the rice cake implies a better crop.1 In parts of Anhui Province, people reward the best sower with cooked chicken heads, representing hope he will lead farmers in better faster rice sowing.2 Hunan Province wives cook salted eggs for their husbands in the first day of rice sowing, the egg symbolizing the rice grain growing egg size.3 The Hani of Yuanjiang, Yunnan Province, die rice stick cakes yellow and eggs red; inviting their friends who help sow the rice to eat them, and ensuring rice has the same color as the rice cake and grains as big as eggs.4 Similar symbolic cooking rituals are also found in Yunnan's Fumin region where a little white "rice" flower picked in sowing season is boiled in water later used to cook rice, a symbolic wish that rice will grow as plentiful and large as the flowers.5 On Lantern Festival Day in Shanghai's Songjiang region, farmers make a special sweet dumpling bigger than usual, often bowl size, in the belief it increases rice crop; the bigger the dumpling, the better the crop.6 The above are imaginative examples linking food customs to rice planting and a wish to have a good crop. The imagination uses similar shape, color, euphony and natural traits of certain food and rice as symbolic wishing for a good crop. When food symbolizes a wish to have a good crop, imagined things seem real and the wish seems to be on the way to fulfilment.
There is much symbolic ritual in dietary habits as intercedents for fruit crops. While not a main food, people like fruit color, appearance, taste and symbol of achievement; e.g.s, "fruits" replace "achievements" in "many significant achievements", while "rich fruit" refers to career success. They pray for a larger crop by eating special food and performing eating rituals; e.g., daubing a fruit tree with special food, where this feeding will grow many branches and leaves, thus bringing a good crop. This is why so many people symbolically feed fruit trees. In some jujube growing regions in Henan Province, this tree is fed porridge on December 8 morning (Chinese lunar calendar), symbolically increasing next year's fruit.7, while Shanxi Province people feed fruit trees meat porridge on the same day8. More pragmatically, Man people cut part of a root and putting porridge in the cut9, Hunan's Dong people feed fruit trees rice on New Year's Eve, cut the tree and put rice in the cut10, while west Hunan's Miao people cut the tree three times and insert rice.11 Guangxi Province's Zhuang people feed trees sweet rice dumplings early New Year's Day, placing them on the ground under the tree, putting soil on them and singing "this tree celebrates New Year's Day; please eat sweet dumplings first so you will bear sweeter tastier fruit." People eat dumplings later.12 The She people feed trees on the first winter day by pasting sweet dumplings on barren ones to bear fruit.13 While food, performance times and players vary, all rituals represent a wish for more fruit, their common nature being fruit trees reproduce like human beings; so better food will improve the harvest and bring tastier fruit.
In Chinese dietary culture, tea, cotton and silk worm growers also perform feeding rites. Tea is important in Chinese daily life, not only as a beverage, but a social function; e.g., greeting guests with tea; performing tea rituals in an engagement ceremony; using tea as an offering in funerary and religious rituals. As its important role in daily life and social rituals raises production concerns, symbolic rituals are performed to intercede for a good crop. Zhejiang Province growers offer the first cup from the current crop to the kitchen god, placing a cypress branch beside it to symbolize "new tea and new crop," and "evergreen cypress leaves and everlasting tea."14 On New Year's Eve, people offer the best tea to their god to protect their plants from natural disaster and ensure a new crop. In cotton and silk worm growing, other foods perform similarly. As cotton and silk are important for making clothes and other things, good cotton and silk crops are desired. Guizhou Province's Dong people, especially newlyweds and single young people, lunch on eggs when sowing cotton to spread as many small white shell pieces as possible in the field to symbolize quick growing cotton.15 In Zhejian Province's Jianxing and Huzhou regions, rice balls are offered to the silk worm god. After selling their silk worm cocoons, people eat a special food called canhua, a rice-bean mix with dried fruit, to ensure a better crop16, while in east Hebei, silkworm cocoon-shaped flour balls are eaten to ensure a better cocoon crop.17 People express their wishes to have a good crop by eating this symbolic food in a certain season.2
The growth of agricultural crops is always affected by the natural environment, especially weather. Good weather brings good crops, bad weather brings disaster to both crops and humans. While everything is done to enhance irrigation, farmers pray for good weather, but mother nature has as many faces as people can imagine and people appear helpless when faced with natural disaster. The old saying of "no matter how you plant your crops, the weather will determine your crop" reflects farmers' faith in its influencing their activities, plus agricultural uncertainty.
Farmers developed various ways to intercede for good weather and crops; i.e., predicting weather through eating rituals; e.g., observing water content in certain foods to assess the amount of rain in a certain month. On January 10 in southeast Shanxi Province, people predict rainy months by steaming one flour bowl for each month (at times 13 in the Chinese lunar calendar), checking each bowl for water when done. More water in a bowl means more rain; no water means drought.18 Similarly, 12 cups of water on a stove on December 30 in Sichuan Province's Neijiang region are checked for water on New Year's Day to predict rainy months.19 In Ningbo, Zhejiang Province, water tanks are filled New Year's Eve, representing a wish for future rain. Another rain predictor is checking for moisture in a bowl with rice or a rice bun in its container after 15 days. If present, the coming year will have more rain; if absent, it will have drought.20 In Linyi of Shangdong Province, if several yellow beans placed in flour lanterns made for the Lantern Festival are steamed, people can forecast annual rainfall based on moisture content.21 Similarly, the Miao of Guizhou Province put 12 yellow beans in a bamboo pipe, pour water into it and 15 days later, observe moisture to assess monthly precipitation.22 Yunnan Province's Yi make 12 rice dumplings on New Year's Day, one bigger than the rest. After placing in boiling water, if the biggest one's movement is vertical, anuual precipitation will be good for rice. If movement is horizontal, there will be much less rain than needed and corn will be planted.23 In all the above rain predictors, food moisture content or its change symbolically equate with rainfall, farmers using this symbolism to predict future crops.
In addition to rain prediction, people used symbolic food and its ritual to prevent floods, hail and insects; e.g.s, Henan farmers avoid flood by shunning steamed bun soup on the first five days of each year.24; Miao people avoid soup with their rice on New Year's Day because it brings more rain than needed for sowing and floods rice fields.25; and north Henan farmers stop drought using an eating rite. Believing it is due to the turtle ghost drinking all water in the Dragon King's well or rain source, people make flour turtles and boil and eat them to kill turtle ghosts and bring rain in three days.26 For rain, the Miao offer fish; the Yi, chicken, sheep and rice. To avoid summer hail, Shandong people avoid hot food on Pure Brightness Day27, while Henan people won't make flour ball soup on February 2nd.28 To counter weeds, the Zhuang of Guangxi Province and Miao of Guizhou Province avoid green vegetables on New Year's Day because it brings crop failure and weeds,29 too many to clear.30 Zhejiang watermelon farmers do not eat dried vegetables on sowing days because it withers watermelon plants.31 Guizhou Province people avoid stick rice in sowing season because it withers rice leaves.32 Basically, people avoid certain foods at particular times because they link to natural disaster. By avoiding certain foods on special days, they avert natural disaster and their crops prosper.
While crops need good weather and natural conditions, farm skills are more important and hard work is needed in farming. In dietary culture, some rituals reflect values and relate to special food; e.g., Zhejiang's Jiangxia people eat rice jelly on the first day of summer because "jelly" in Chinese has the same pronunciation as "ploughing". This homonym implies sowing season commencement33 and that eating jelly ensures successful sowing.34 The Tu of Hunan Province make a special plough-shaped rice cake on December 27 (Chinese lunar calendar) to symbolize paddy ploughing.35 When the Miao of Yunnan Province prepare holiday meat in December, pig heads are saved for a special meal on January 15, when they stew them to assure farming plans.36 As part of their dowry, pre-nuptial She clan girls in Zhejiang Province collect rice, yellow bean and peanut seeds to bring to the bridegroom's home on their wedding day to symbolize the brides' start and bearing fruit in the new home, plus their working together to increase crops.37 The above eating rituals have the same symbolism: hard work increases crops.
In Chinese dietary culture, the traditional agricultural view is expressed in eating rituals and customs reflecting hard farm work. But ritual also reflects agricultural limits unprotected from natural disaster. All reflect interaction between dietary culture and agriculture.
SOURCE: The Traditional Farming View of Chinese Dietetic Culture (RTF DOCUMENT) or VIEW AS HTML
Getting back to Jackie's picture of people in the fields - I can't find out much (at least not without spending the entire day searching) but some of the reading I have done suggests that either it is a tradition associated with driving pests from the fields or associated with asking for rain. Either way it is definitely associated in some way with ensuring/asking for good crops.