When you see a girl with an awesome big booty, but she has a small head not proportionate to the rest of her body.
Carlos: Damn, look at that booty.
Lou: I know! She's a tiny face. What up Tiny Face!
The animated sound made while executing a donkey punch.
Think comic book. "As he wildly made love to her from behind, she kept talking.... frustrated he decided a donkey punch was necessary ...kaDONK!!! and that was the end of her conversation."