Specifically I would like to do this for playlists. I would rather link to the playlist itself, and not to the first video which might not actually show a description of the play list. Plus I may want people to start with a later video.
It’s fine if whatever it is would only work on playlists, but a general solution would be cool.
Test https://www.youtube.com/playlist?list=PLLc9pB32V1Qh-pBbd-dhjvkK9odDWEaup
ETA, so far that’s the closest I can get, breaking the preview so you have to go to youtube. I don’t know if it’s a function of youtube or discourse, but something sees a playlist and assume you want to start watching it and not ‘here’s my playlist, pick a video from it’.
Here’s your answer, at least as of about a year ago Add thumbnails for YouTube playlist URLs - feature - Discourse Meta
“For normal YouTube videos, we use a custom embedding system. This doesn’t support the playlist UI. So that explains the difference.”
Yes, just put the link in brackets like this
https://en.wikipedia.org/wiki/Death_during_consensual_sex
<https://en.wikipedia.org/wiki/Death_during_consensual_sex>
if you don’t do that, you get a onebox: