Most customers don't know what you look like.
Sure, there are the occasional few who leave greeting cards on the windshield of your car or look up your number out of the phone book, but I always think of those as stalkers who just happened to have eaten at one of my tables. The real customers wouldn't know me from Adam. Or Eve.
To prove this point, one night Suzy, a waitress I worked with at the pancake house, smeared fudge sauce all over her face, sprayed on some whipped cream eyebrows and stuck a cherry on the end of her nose (I think she had sprinkles on her cheeks, too) and brought a fresh pot of coffee out to her new table.
"Hi folks, how are you tonight? May I start you off with some coffee?"
Barely a nod and a grunt. They kinda motioned at their cups (I guess that was to make sure she didn't pour it in her shoes) but they never even looked up at her. When she walked back to the service area, we were all practically falling down from laughter. Suzy just wiped her face off and walked back out on the floor to take their order.