Open Graph
Open Graph is a set of statements in the source that decide what a link looks like when someone shares it on a social network or messenger: title, description and preview image.
Without them the platform guesses. What comes out is often a fragment of a title, a random image from the page, or none at all — and a link shared in a group looks like a mistake rather than a business.
Image size matters, and so does giving every language version its own statements. Attach the German description to an Italian link and you waste the exact moment in which someone decides whether to click.
One caveat belongs with it: whether a platform picks the statements up is its own decision, and many hold on to the result for a while. After you swap an image, the old preview can stay visible for days.