Well out side the fact he is missing his head and the pictures are crap.
His pasterns are long even as he grows does not look like he is growing in to them yet. Still might. I do not like his back or withers but again might just be the pictures as he is not standing very well.
Without is head and neck in any of the shots it is impossible to tell if he is well balanced or not.
What you need to do is find if you have them pictures of him standing nice at each age and include his head along with the rest of the horse.