Welcome to BPN. Handsome bird, soft background, but with some detail adds depth.
Things to consider: He is looking away, somewhat less engaging, The light angle has resulted in fairly shaded underwings. The bird isn't particularly sharp, and at that shutter speed, motion blur is really an issue often. Normally a shutter speed 1/2000s and up for any flying bird, depending on the angle and motion of the bird at the moment of the shot.
The secret is to keep working it. There are lots of great images on BPN to learn from, and to apply to your own (or son's) images.