I don't typically offer my opinion on the critiques, but I felt that I needed to on this one. Because not long ago I looked like you do in the first picture (more or less). What I noticed is that:
1. Your gripping with your knees.
2. Your consistency is not there.
3. You have no release.
But I do love how you keep your eyes up. :)
The main thing that I noticed though.. is that in the first picture especially, you look like you're cringing with your shoulders. You're tensing your body and locking your arms so there is no release there. I have a bad habit like this that I've been working my way out of. It's just not stable. I'm guessing on the backside of this jump (I mean landing transition) You probably had a bit of an inflata-back which is what I did.
What I've found helps me tremendously is a stride or two away from the jump think "Heels down, don't throw yourself over the jump, relax, release, BREATHE, and open up your shoulders." This change has helped my horse with jumping so much, he used to take down rails all the time and that is why, we haven't had an issue with it for a very long time now.
Other than the things I listed and said by everyone else, that's about it. Keep up the good work, you're looking pretty good. I would love to see some new photo's/videos. See your progress. :)
Edit: Also, in the new set of photo's you look like you have improve quite a bit, pulling your shoulders back, you look more relaxed as well.