why is this the OG preview

no idea, that is odd. from searching i see that that preview comes from this post from 2023 (who’s permalink is on a domain which no longer runs lemmy; the instance which was feddit.de is now feddit.org).

if you look at my post made today here on lemmy.ml it has the correct thumbnail from wikipedia.

when i browse my lemmy profile via your mastodon instance i see that my first post of this same wikipedia article (to [email protected]) does render correctly there - it is only this cross-post i made to [email protected] which has the wrong preview. (if you figure out why, i’d be curious to know!)