Does anybody know why and when thumbnails for YouTube videos are shown or not? It appears to depend on the lemmy instance the posts are served from:

Without Thumbnails

With Thumbnails

Update: It’s not only YT thumbnails which aren’t shown. This is your post about the free 24 slot bag as shown on lemmy.wtf (without thumbnail), lemmy.world (without thumbnail) and feddit.de (with thumbnail):

  • Necropola❌OP
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    1 year ago

    OK. Looks like the CSP headers are the same on working and not working instances.

    What I found surprising is that chrome loads the thumbnail without accessing the actual YT URL (contrary to what I expected) from the “pictrs” server of the instance serving the post. Which means that the thumbnail gets only extracted once and is then stored along with the post.