Anything somewhat dangerous and new gets a lot of attention these days. Anything that deviates from the routine is enchanting. Looking out the window was one of those things, and if there is enough going on outside (like our huge renovation a couple weeks ago) it keeps his attention for quite some time.
It's activities like these that make me wish we didn't have a TV. Television has its place, but I hope that when life gets crazy we don't forget to take a minute and look outside and let our imagination be captured and our senses excited to God's magnificent creation. There is a lot more to be learned at the window than at our TV.