We have a long-standing policy about strongly preferring self-contained puzzles. This meta is to revisit that policy. It was inspired by a chat debate about an enigmatic puzzle by @Feryll. The puzzle originally consisted only of a line of text, then a multiline link to a YouTube video. It has now been edited to contain a text and image description of the video.
Please browse the Q&A in my first search link to see how we've applied this policy over time. There's the obvious: requiring the download of software or going to random external websites isn't allowed. There's the maybe less obvious: requiring going to a personally-hosted site isn't allowed. There's the exceptions: metapuzzles which rely on previous Puzzling-posted puzzles (say that five times fast) and images hosted on i.stack.imgur are fine (as are those hosted on imgur if i.stack.imgur is impossible). This is not a comprehensive overview of the policy.
Where does this puzzle fall (both before and after the edit)? When we previously considered puzzles that included videos/audio, the consensus was that puzzles which completely relied on the external source ran afoul of the policy. Should this consensus apply to the puzzle in question; should it be reversed? Should or must we update our general policy on this? Discuss! It's meta, after all.