Sarah, I know nothing about nothing, but I don't think he has a problem with his top line now. I think if you had someone else to take the pics and you could hold his head in the same position the person held it in in the 10 week old pic and you held his back side and front and back legs in the same width apart as in the pics his top line would be the same. Just my opinion.
Could be that. Craig wasn't there to take the pics while I held him so I just tried to take as many shots as I could in the hope of getting a couple of decent ones.