I am as ready as anyone to castigate abusers, but I agree with other posters that those photos, at least, aren’t convincing to me. Based only on what is shown in them, it looks more to me like a horse that had an allergic reaction, or perhaps had a run in with hornets, and/or maybe got banged up in a stall/turnout/trailer and is possibly sweaty due to sedation. They’re certainly not flattering pictures, but without context it’s impossible to tell whether these are the results of abusive riding or from an actual medical incident. Perhaps there are more pictures than what are shared in the video. I don’t know anything about the Strassers, so have no particular context or opinion regarding their training or riding.
Either way, I hope enough additional evidence comes out to either result in punishment, or establish that there wasn’t abuse involved.