…who/when would you show it to? And why? (The person/people in question would only be able to view it once and not be able to pause it, but it would be allowed to cause a butterfly effect and change the present.)
I'd probably show van Gogh, when he was really depressed, this video:
I'd do it in hopes of kind of recreating that one moment from Doctor Who except hopefully it would be a happy ending instead of a bittersweet one. Plus, this way, I don't have to worry about completely changing the present too dramatically. Either nothing changes or we get a few new paintings and a happier biography from van Gogh.