Retail Face
No matter how sad, depressed, angry, or tired you are, the moment you have to face a customer you put on a smile. Other signs of a Retail Face are: a happy tone to your voice, saying that you are "doing good" when asked how you are doing, and laughing at customer's bad jokes so they won't complain about you to the manager.
"You seemed pretty happy getting yelled at by that customer. Must have your Retail Face on, huh?"