This is next to useless on the dressage-vs-western thing because I know very little about it, but I wanted to say that I think your horse is very handsome! The small amount I do know about is that you do not look like you are sitting him in a western seat - I'm a Texan, and have spent a fair amount of time in Western saddles and in my experience at least, that involves sitting more "back" on the horse - I'm learning hunt seat right now, and the posture you're using on him is a lot more like what I am learning than what I'm used to from a Western style. Also, I do not think this is the head and neck position from the horse that I'm used to with the Western riding I've done and seen. He looks like he's got a more...I don't know..."formal"(?) configuration there.
I do think the two of you look really good together, though!