I have looked through the app I use (mlem) and the web interface but I can’t figure out how to give a link post an image, as when I try to put something into the image section it replaces the link.
So how is it done exactly? Is this some setting, special script or app feature I don’t know about? Or have I missed something?
It all depends on the Lemmy server making the fetch. Many Lemmy instances are run from various VPS’s, and sometimes sites block IP ranges from certain cloud providers or Cloudflare might not let them through unchallenged. If the server can’t fetch the details, it won’t have the thumbnail image.
I think it also depends on the instance’s pict-rs configuration as well. If the thumbnail it fetches is larger than the max size configured for pict-rs, it won’t fetch it. There’s some other weirdness with that process, but I’m not sure enough to even try to explain it lol.
Ah, thanks so much for explaining! This makes sense, yeah.