The primary school teacher forced the children to hand in photos.

Now I don't know why, a small number of primary school teachers regard children as tools of honor, thinking that children are easy to cheat when they don't know anything, and parents are innocent. Your friend did the right thing, but it is worth mentioning that you can't confront the teacher head-on. This kind of teacher is shameless. If you don't follow the requirements, he may be unfair to the child and need clever methods to solve it. It should be said that it is more appropriate to suggest your friends to involve other children, or to involve them.