Wonderful suggestions! Thanks. I think we'll let the photo speak for itself, and put a list of the captions on the backing of the frame.
(I'm glad you said that, my wife agreed. There's no need to limit the expressiveness of the boy with a single caption.)
Kids are great models, and my grandson is very natural and expressive in front of the camera. But of course, the fact that he's ours is a huge bias. I guess I should fill my cell phone with his photos (and of course, some hummingbirds too) so I can bore everyone I meet.