@strk The preview for links is fetched by each server separately, so if a link is shared to a server after you made the change it will show the newer picture. If the link was shared to a server before the change, it will show the older picture.It will eventually refresh, and I think the admin can speed it up by altering the length of the media cache, but you would need to do it for every server separately and cause additional traffic as lots of other links would need to be refreshed.