Why do photographers make people shake from side to side when they take one-inch photos?

I want to be a professional. If he doesn't say anything and you just sit there, it's usually not good. When I take an inch photo, my head often leans to the left, but I didn't realize it. Every time the photographer reminds me to turn around, I hunch over and don't smile every time I take a picture. It looks ugly. I can only do it if the photographer reminds me.