I've never known a little boy to be so happy to pose for pictures.
I guess someday he will not want to sit still for it, but for now he loves having his picture taken as much as I love taking them. He'll happily jump from one lap to the next and flash you a big smile. Then he jumps down and wants you to show him the picture.
I guess that's one more good thing about digital cameras, kids get to see the result right away of sitting still for a picture instead of waiting for film to be developed.