The ox (Niu) is the second symbol of the Chinese Zodiac and stands for power. Niu also stands for spring, the season where the fields are ploughed with oxen. Spinach & egg is the name for the decoration of green, yellow and purple that is applied in stains on the biscuit. The name was coined by traders that saw a similarity between the decoration and the dish with the same name.
Chait Galleries, New York (according to a label on the inside)