This photo was taken in Guanling county (关岭县), Guizhou, in December 2013.
An explosion provoked by the opening of a Chinese kernel popper. This device made of cast-iron is powered by coal and swivelled by hand. According to Wikipedia, in the process of popcorn making “the maize expands from the kernel and puffs up when heated. Popcorn is able to pop because its kernels have a hard moisture-sealed hull and a dense starchy interior. Pressure builds inside the kernel, and a small explosion (or “pop”) is the end result.”
In the case of the Chinese popcorn-maker, all of the popcorn explodes at once when the cover of the canister in which the corn is heated is opened and a sudden depressurisation takes place, making the kernel swell, puffing as a result. The whole process takes about eight to ten minutes to complete. Popcorn poppers like the one in the photo are a common sight in the streets of many cities in China. The object captivates the passer-by, as it brings to mind a device from another era.