Shop istants applying makeup at work, appropriate or inappropriate?

I'm just realizing more and more shop istants is applying make-up while at work, especially ones that sell beauty products like the body shop. It sort of puts me off the products seeing the istant(s) just applying some of the testers while there are customers in the shop (and the testers aren't there for they're own personal use). Can't they just do their makeup at home like most people do. I was a shop istant before and I never had the need to do my makeup at my work. What do you think is it acceptable or just plain inappropriate?