1. Messing up the background. What? Not shot straight on with a window in a background to reflect the strobe? No pile of useless-to-the-photo junk lying around that a rocker would have? And a clean hardwood floor rather than grubby carpeting?
2. Hopelessly bad light. I like the hard light in this one and the conflicting shadows. But hard rocker guy is only gonna have one light, built into the camera and about one stop too bright, or available light. Preferably both with fluorescent ambient providing a sickly green accent. And where’s the red eye?
3. The squawling, messy-faced baby. Your baby is too angelic!
4. Dull composition. Look at the nice line from the tree through your face, to your wife’s face, and back to the baby. And it’s framed so tightly on the subjects. Extra space around the subjects could be filled with irrelevant (hopefully embarassing) details.
5. Bad focus. I’d say you’d want the auto-focus to grab the closest possible object so everything else is just a little soft. I think maybe the front wheel of the chair would be good here.

Fun stuff, but there’s always that fine line between winking at people and mocking them. My wife and I wrote a phony Christmas letter (summary: everything we touch just turns to gold!) that we didn’t have the nerve to send to anyone.