I might see how this could work with a movie or music file, but not an image. The premise behind the value is the exclusive ownership of the image. But you can just screenshot it. I don't understand how any notion of "ownership" factors in here.
A: Otherwise pointless authenticity.
Q: So why do people spend so much effort identifying forgeries?
A: Because people, for some terrifying reason, value otherwise pointless authenticity.
For example: Sweepers Clock is a video sold as a limited edition art asset today, using a paper contract and traditional auction houses. It's very hacky and buyers often are worried they'll just "print" more copies, but it still sells and has value. I think rare digital art would be perfect for this kind of thing, less so a Hollywood film.