It looks like your lower leg stays put at the girth and you keep your heels down well. Good! It's kind of hard to tell with your over-the-helmet-head-warmer-thingie, but it looks like your eyes aren't always up and looking where you're going. In a couple of the still photos, it looks like you're looking at your horse's head or at the ground directly in front of you. =) Nice seat though!