Each day when he pulls out the pink tower to work I re-present the work by stacking it properly one time. I then take it apart and he practically starts rebuilding before I'm finished. He constructs the tower at first by picking up whatever block is closest to his hand, but quickly notices that it isn't stacking correctly.
Try to ignore the gigantic amount of static in his hair. He has looked that all winter long, no matter how much I try to get his hair to lay down.
Once he notices that the tower isn't going the way it is meant to be stacked, he usually knocks the whole thing over and tries again. In the last few days though he has been trying more careful and only removing the blocks that need to be changed. It's been fun to watch the progression in his thinking, but at the same time it has been hard not to help him along the way.