Finally I just went with something, but I wasn't totally happy with it because you couldn't see his whole face:
So as a backup I picked this one, which is cheeky, but I think really personality-laden.
This caused strife in the household because DH feels the second picture is totally inappropriate for a holiday greeting. I finally had to do something which I hate: I pulled rank:"You haven't been involved with the holiday cards for 3 years so ... pbbth!"
Lets all agree, the second photo is NOT the one you send to your boss. Or the 2nd cousin you only see at weddings and funerals. They get the 1st photo. But close family members? I see nothing wrong with it. How about you Internets? Lets take a poll, shall we?
Holiday Greetings: Good place for tub pictures or not?
Not my taste but its your kid!
I'm just happy its not a dog with antlers!