Why is it called "Shayan" kite?

The representative work of Beijing kite is Shayan kite (also called Jingyan kite). The head of "Sha Yaner" is a plane deformation of the swallow's head. Its eyebrows are raised, its eyes are full of gods, and it is endowed with human feelings. Together with the pair of scissors tails, it makes people look like swallows. It is cuter than a real swallow, and people tied it into a fat sand swallow and a young swallow according to the "big fat boy" that everyone likes; And according to the slim and graceful girl, she became a "thin sand swallow".