just as an FYI, someone made a tool specifically to preview what twitter was going to do for a card when you gave it a link:

https://cards-dev.twitter.com/validator

It seems like Twitter made a tool to specifically do this, not just an altruistic individual.

I think ultimately you're getting to the _why_ of the equation - there is a big desire to keep you, the customer, within the app rather than let you abandon the feed. Going back from a note to scrolling through Twitter is easier than jumping back from your browser app to the Twitter app.

I haven't had issues with link previews on my own content, but that very well could be the case for other sites.

As a non twitter user but searching for my site a few times I've always wondered why that is and what I am doing wrong. I didn't know it is a general issue since I don't use it.

> Do you know that Twitter still does not show link previews reliably?

This seems like it might be a somewhat good thing, for privacy. User generated trackers could be included in topical tweets.

Is that image not just resolved once, while posting? I remember Apple solving it in a similar way for iMessage - the sender always generates the preview.

I would assume this is what they do. Places like Discord and Facebook will usually cache it on their CDN and display the image from their CDN.

Even if I direct link an image on discord, it essentially just rehosts that image on their CDN and displays it from there. Discord even allows that cached image to be hotlinked on any site. I have seen people use it like an image host for things like their "signature" on forums.

I've seen embedded videos auto play directly from external sites, in the app. Making the video fullscreen just expand what appears to be a frame, with ads and all present.