Is it normal for a hairdresser to take photos of you?

I hope so. Hairdressers have sometimes said that cutting my hair is easy because it's very straight and dense, and I tend to neglect it rather than subject it to heat or chemicals (to the point of air-drying after washing, even in winter). And I don't have issues with sitting still. I like to hope that my hairdresser would have taken the pictures to use as teaching aids for her trainees...