I know there's a post on SCNA on how to tell if your bird has a short or long back by placing your fingers between the tail and neck there. I think though that your guy is still a baby xD. Correct me if I'm wrong, but my understanding was that they can change on you. I'm not experienced enough to make the call on your bird, but maybe you want to post it in the SCNA critique forums? They may just tell you about tailset and wing angles/length and to come back in a few months. Or they might tell you something more in depth, hehe.
As for scale, I put a chick next to a can of coke once and took the pic...hubby got on me because I didn't have the chick RIGHT NEXT to the coke, so it's harder to tell perspective. You did the same thing I did in this picture. Minus the keyboard.
BTW, does anyone know how to make them stand without scaring them with a cat, quail or dog? I know it sounds bad, but that's the only way I've ever seen any of my guys pose (it wasn't intentional...well maybe with the quail)...