Well, its not the best angle to critique from. :) But you are right, you're giving him a bit too much rein and judging from your profile pic, it looks like you ride him on a loose rein anyways. If you trotted him to the fence, that could be the reason his knees are uneven or he may just be sloppy or if he's an older horse, his knees may be a bit arthritic and don't want to bend. I do like your back if the photo angle isn't lying to me. Its nice and flat. I also like that you are keeping your fingers closed and aren't opening them up when you release. I have that bad habit and have crunched my pinky fingers a few times. ;) You are, though, jumping out of the saddle here. Bring your stirrups up a few holes and let the horse do the jumping for you. I know lots of people say stay in two point to the jump and over it, but that never helped my jumping ahead of the horse's motion. What really helped me was staying on my horse's back--not pounding on his back--but lightly in contact so I would remember to stay back and it would keep my in time with his rhythm.
Opportunity is missed by most people because it is dressed in overalls and looks like work. ~Thomas Edison