I think it's pretty much perfect, but since you asked for things that might be amiss ...
"Dad" looks more like "Mom". His lower face is not giving us the visual cues for "male". Before I read the description I thought they were two women (and that it was a picture of a living girl and her doll. "Dad" is one hell of a realistic toy) Obviously you can't change the toy's structure, so perhaps make his eyes visible, style his hair a bit differently (read as: more masculine) or give him more masculine clothing.
The difference in skin tones between the girl's hand and the dad's hand is ... freaky. Just sayin'
A big one for me is that he is not holding either the violin or the bow correctly. Violin should be under his chin. You should probably find a chart showing you how to correctly hold a bow, as the instructions involve specific parts (I.E. The "Frog") that you probably wouldn't know. I did consider that perhaps he's holding the violin low so his daughter can put her chin in the rest and pretend to play. If this is so, she should be interacting with the violin. Her other hand is hidden in Dad's sleeve. Perhaps put it on the fiddle and bring her head a little closer to the chin rest.
Also ... Dad looks real ... if ... rather like a girl. The little girl looks like a doll, both with her general look and with how she interacts, or rather, doesn't interact with the rest of the stuff in the photo. Again, giving her a more active pose might make her seem a bit more lifelike, as would exposing the father's eyes to the camera.
But that's just me being nitpicky. It's a good photo.
About the dad looking efeminate, in the truth is quite intentional see?
They're asian ball-jointed-doll models and almost all the guy-dolls on this doll hobby follow an androgynous esthetic.
I tried to make her look like was interacting with the violin, but i agree she ended looking much less 'lively' than him >_< thanks for pointinhg me this, i feel it was one of the 'amiss' facts in the photo.
Well, sometimes "amiss" is subconscious, and to me, missing gender cues are one of the things I've trained myself to pick up on ('cause my guys usually look like girls unless I REEEEEEEEEEEEEEEEEEALY push it) so naturally, that's one of the things I check when I hit "doesn't look quite right".
It's a cool hobby, BTW. I would involve myself if the damned things weren't so expensive (that's like, half a month's rent. I have that much free money, I buy food and books)