He's trying to take his shoe off with a screwdriver.
His father calls this one Sextus, but I rather like "Piglet" (like from Winnie-the-Pooh) because I always identified with Piglet's smallness and general confusion about what was going on, and I sometimes see that expression on this kid's face, too. We did monitor him to make sure that he didn't poke it in his eye or toddle off to an electrical outlet, and we did eventually take it away, but not before I got a picture first.
A few more pictures from the Provo trip shall follow (I hope).