Not weird at all. In fact, the first thing that struck me in looking at that page was that those pictures look like some more nice treasures from Stephen Clark's (the guy who runs BTTF.com) archives. I was talking with him in person at the DeLorean Car Show in Orlando in June, because he was selling 2015 hats and had a really nice picture as a display of Marty in the jacket and hat. Really nice quality and posed, not just a frame grab or any picture we've all seen before. When I asked him about it, he said that he had a bunch of pics that are not "out there" and that was the nicest one for his hat display.
Sigh... I wish he'd share more of those, as you can see they're great. They look like nicely posed still shots taken on the set during filming. Maybe if a few of us bug him?