Ok - so you were working on poles, so your leg positoin is correct than, and since you are in a jumping saddle, your legs are correct - at the girth.
Ok so your flat picture - Your legs are great and where they should be, which is at the girth for the job you are doing. I like your iron placement as well, they are where they should be which allowed your ankle to do it's job, which allows your heels to do their job.
But don't grip your knees. Re-establish what part of your leg is supposed to be doing what.
Take these rides over poles in the outdoor arena as an opportunity to solidify your form - so that you can be that much better over fences.
Open your knees, and use your inside calves instead. Really focus on solidifying your lower leg.
Your toes, are pointing outwards - which shows me that you are using the incorrect part of your calves.....you are using the outter calf, instead of your inner calf. Again - re-establish that.
Your seat is nice - you are on all 3 points, your 2 seat bones and your crotch - and that is how it should be. But I am starting to see a hollowed out lower back, you've now allowed your bodies center of gravity to leak out the front end of you.......straiten that lower back by pulling your tummy muscles inwards. Use your core - without your core, you have an ineffective seat.
Your upper body, is just a more forward than I like. While you have to remain just a smidge ahead of the verticle to learn how to stay with your horses center of gravity for when going over a fence, you don't want it to be too forward - because then you loose the effectiveness of your seat and you also put your bodies weight onto your horses forehand....which makes it that much harder to keep them light.
You already mentioned your hands
Lets go back to your legs - you have to learn to use them correctly, to get your horse moving correctly. Remember - jumping is dressage with speed bumps.
Your horse is stiff, his back is dropped, hind end is high, head is carried high - and is reacting to your riding.
Seat into legs into hands to soften.
I can elaborate more later, I don't have much time because I have to head to work.
Your jumping - again, I will have to come back later when I get home from work :)