the horse looks happy and forward and relaxed. He is on his forehand, but not in a forced way, and you both have the look of a great intro/training level pair.
Looking at his front feet, his front hooves look really long with what appears to be underrun heels. can slow down his breakover and make it harder for him to reach underhimself.
you do need to look up and open your chest a bit. it's kind of like you are generally rolled forward, inward, in chest, neck and even your knees are up and forward, like a "C". you can start by putting your thumbs on top. that's very helpful for reversing the inward "curl" of body and mind. Look up. roll your shoulders back a little. .
To get more of your weight down into your leg and ankel, take you legs out of the stirrup, let them hang down. lift the thigh out and off the saddle, then let your leg go back onto the saddle. without moving your upper leg, reach up with your toes and find the stirrup. let your leg hang down into the weight going down through your ankel. no pushing, just hanging.