This honestly just baffles me to no end. Not allowing visuals to spread of a public demo that is, by definition, an advertisement, preview, and hand engineered incentive to buy their soon to be released product (i.e. increase interest, support, awareness, and excitement for this game and it's subsequent showings/tours such as this) doesn't make any logical sense. If it's cause the build is outdated or of pour quality in some way (certainly not because of spoilers, right?), either don't release it at all, or replace it with another demo. We're also in an age where things like image/video leaks are incredibly common, so I would've hoped that there must have been anticipation of this to some extent. It's just basic proactive thinking, and a company's oversight should never be to the of detriment of it's fans/supporters. But what's done is done I guess. The human factor is a thing, so I'll just leave it at that.
Edit: Forgive me if I was regurgitating a lot of what was already said, I hadn't actually checked the other post till afterwards.