That video is a good example of why the WD movement grates on my nerves. There was nothing western about what the horse was doing or how it was being ridden. I have no objection to folks riding dressage. It isn't my cup of tea, but so what? But calling that "Western" seems dishonest to me.
I think calling that "dressage" is also dishonest. I completely agree with that grating on nerves...
As a dressage rider, that just makes me cringe. If that is "dressage" that is all wrong. Right off the bat, is that supposed to be half-pass at the trot?? A leg-yield?? Sorry, last time I checked, half pass doesn't lead with the haunches, and neither does leg yield. Whipping the haunches around and moving sideways is so not correct. For either of those movements. In the canter, is that a canter pirouette? Pulling your horse into a tiny circle isn't a pirouette. The changes are all late. The "contact" is just bit leverage. Pulling on your horse's face to shorten it's neck and make it upright is not collection, or correct contact. That horse is not anywhere near tracking up either (because of the "contact" or "collection"...). I could go on and on.
Take the western tack off that horse, put in in english tack, throw it in a 3rd/4th level test (because those are the movements she is kind of showing here) and it would get absolutely ripped apart by the judges.
I hope this post doesn't come off as incredibly rude, as that is not my objective. I'm simply incredibly surprised that this is "Grand National Western Dressage". To me, that implies that she is a more advanced rider of this new discipline. This rider does not do either of these disciplines justice, imo. As many people have mentioned, there are already disciplines in western that are like dressage. Incorporating dressage principles to your western training can't hurt, if that is what you choose to do. But to make a new discipline? I feel you're losing what distinguishes each discipline by mashing it together into something new.
Sorry for the novel, I hope I haven't offended anyone
ETA: I would be interested in seeing some better examples for western dressage. It certainly could be interesting to learn about, and I do think that it could open avenues for riders who aren't looking to go FEI in dressage, but would like a feel for it at the lower levels.