the pictures are taken at the wrong moment so i can't judge on his jumping.
as for you try not to go so much forwards during the jump, and sit straight otherwise you disturb the horse his balance.
make sure you loosen your rains in time, as you can see on the last picture he is not using his back, he is making it hallow.
These are just a few tips
But you've got a baeutifull horse, and i'm sure you'll get far with him!