Ditto- I think the teacher is trying to make sure that the child is reading at home. I think ALOT of kids do zero reading at home that isn't forced on them. I don't see that the teacher is trying to control what they read or anything.
My first grader is doing the little reading contest at school. He is reading 3 books or chapters in books daily, for 4 months, to get to the target of 400. The books are at (or in his case, 1-2 grade levels above) the child's grade level.
For him, he's reading 30-45 minutes a day. He's a reluctant reader but... He wants to read silently and we are starting to have him do that since he's reading so well!