How come child labor laws don't apply to children who are actors?

Why is it ok for children to be actors? How come it isn't considered against our labor laws?How come child labor laws don't apply to children who are actors?
Because if you work somewhere like a restaurant or factory, there's machine stuff to deal with. Since when do actors push air conditioners around? They don't. And besides, there are child labor laws for actors. But there's no strictly off limits things. A baby actor can only be filming 15-20 minutes and they have to have a thirty minute break in between.How come child labor laws don't apply to children who are actors?
They do have laws. Well, they do in England
I'm more wondering about if children truly wants to be actors. like Olsen twins. they were barely talking %26amp; walking and they were already watched by millions of people. I think this really ruins the whole idea of having a humble life from the beginning and not everyone watching you how you physically develop from a child to a teenager.