Hi, Im new, but I thought I would offer some advice despite that.
Your position looks pretty solid in general. Your base of support seems strong and you stay with your horse over the jumps nicely. One thing that I did notice though is that it looks like you tend to drop your inside shoulder, a lot of people do that. It just takes some concentrated effort to raise that shoulder and that side of your body. It is, however, something that is important to fix because of its affect on the horse, as they will also become heavy on the inside shoulder and it will become more difficult to balance them. The only other thing is that you seem to be quite stiff in your upper body when you ride on the flat. This could be because you were nervous at the show, etc, but a soft, flowing upper body is nice compared to an overly rigid one. Anyways, you and your horse look great, best of luck in the future!