Jumping ahead (its a hard habbt to break, I had it), legs look like they slid behind your body, nice heels, and you have a long rein so the release is good too. It looks like you were nervous so you tried jumping it for him, instead of letting him bring you out of the saddle. jumping with your eyes closed, and without stirrups work wonders, but make sure you are on a lung line so that he doesn't take off (bad experiences with a horse landing and bolting and I still had my eyes closed...ha ha ha)
Heel came up, leg slid back and toes are out. It looks like you need some more work with your lower legs, so like I said above, working without stirrups is the best thing to do. Perfect release, and I love your back in this pic.
Much better lower leg. It looks as if your squeezing with your leg, so it's not moving, but your toes are out. Again it looks like you are trying to jump for him, because your in front of the pommel of the saddle and it looks like you were pulling up (not positive on that one).
Overall you just have to work on letting the horse bring you out of the saddle. I know it is so hard to break that habbit as I had it myself. But the best thing to do is work on the flat without stirrups and then when you are comfortable jump.
Hope this helps!
O and by the way your horse is sooooooo CUTE!!! I love chestnuts, because I have one myself!