@Jondor As far as I know Mastodon looks for the Twitter meta tags for cards. https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/markup.html
On my site I have both the Twitter and opengraph versions. I get the correct cards in Mastodon.
@tsturm thanks.. As it seems my site code supports some of those metatags, but not all.. Time for some weekend hacking! ;-)
@tsturm After some more research (couldn't wait for the weekend) I see that your toots show the same card as mine do but those are not what I'm looking for,
In your toos there a link to a youtube video which has the "play or go" overlay. This is what I'm searching for. Why do links from youtube (and 500px) show this overlay and why doesn't my site?!
@Jondor Ah! I see what you mean. Youtube links get this big preview that is different from a regular site link card. Hmm.... I want that, too! 😊
Generalistic and moderated instance.