Have you seen that episode of Angel where the muppets suck the life force from children watching them? Then Angel gets turned into a muppet until they figure out who the bad guy is and return the life forces to all the kids. When Nate plays with this toy, I'm reminded of that episode, but I'm not exactly sure what part of the experience makes me think about it,
Something about how Nate stares at it, and then bats at it, and gets a little worked up as though he is confounded by this thing and is trying desperately to figure it out, or beat it at it's own game, makes me think about that episode. When he can see this thing in the room, he can't pay attention to anything else, it's so strange. Some might say that makes it a very effective toy. It definitely makes a great baby gift!