My Mia smiles when we come back from somewhere, if she is excited, and on command. I have never seen another dog do it, it's hilarious! She also uses it to manipulate. If I am mad at her for some reason, she will smile to try to get me to laugh or be easy on her. I will have to get a video of her doing it. I think I might send it in to America's Funniest Home Videos!