speculating here, but the "auto-generated ones" are probably just the ones in the opengraph tags, which is supposed to be what the website intended as the thumbnail. It's more likely that these websites' operators don't have a clue that opengraph is being used, but since they're the "proper" way to do embeds, lemmy can't just ignore them, either.
ernest314
joined 1 year ago
if you use Caddy they even take care of that part for you
I know I'm just dumb but for some reason Caddy is just so much easier to set up than nginx or fiddling with .htaccess files; I'd always fuck something up