Your horse is adorable, first off. I would take him in a second, he seems to real enjoy jumping.
The biggest thing that sticks out to me, is your back rounding forward. At times it's almost bent in half towards his neck, especially in flat work. Over jumps, especially noticeable in the still frames, you look nice; just in between don't round your back!
You look like you're working so hard! While at the canter, you look like you're throwing your body forward every stride (almost pumping him with your seat); think about sitting up straighter and letting your lower body move with him, while your upper stays quiet. If it takes you moving around so much to keep him forward, then get him sharper off your aids. At the trot too, let him momentum push you out of the saddle, you don't have to pull yourself up every stride.
In down transitions, really noticeable at 1:49, work on stopping him by sitting really deeply and resisting him with your back; something to ask your trainer about. You're pulling him to a stop and it's literally lifting your butt out of the saddle, where you should be putting your butt deeper into the saddle to stop him.
I mean this all in the nicest way; sometimes criticism comes across as mean! You guys are a nice pair and really look like you enjoy being together.