So that looks like bittorrent-first. I think in order to introduce this in nostr-land, we would have to do dns-first: Unaware clients just use "https....printer.gif?bittorrent=magnetLink" while aware clients treat the url as fallback.
Discussion
If you do that as a file hoster and get some popular client to use it by default to get this style of links broadly used in nostr, pulling the plug on the original url would quickly drive other devs to add these few lines of code to their clients.
I am waiting for the nostr.build or nostrimg people to add support for this, otherwise I will do it in a couple of years.
Yes, but that's easy to do, as you just showed.
My original point was about the general idea of "sharing files on Nostr", which is different from "rendering pictures", I think.