I forgot to say, my son does something a little bit like this too. After my DD2 was born back in April, he went through a phase where he would move ALL the toys from the playroom and put them somewhere else, but in a really organised way. He would group them together, so he would lay the books out in one place, the teddies somewhere else, then the cars etc. He would also add to it with other things, like hats, shoes etc, all in groups. He would say that he was making a shop or museum. He did it a lot for a few weeks, and he then did it a couple of times around his school settling in visit. I totally think it was a control thing with him as it is very different from the way he usually plays.