I am trying to create Twitter cards using the twitter meta tags (and Open Graph for other sites like Facebook). When I see my twitter feed from others like say NPR News the cards are expanded by default.
However when I post the same content - the card is not expanded by default. I have to click on the tweet and the click on "Details" or "View Summary" which redirects me to a new page where the card is expanded.
What makes twitter decide weather to display the card (in my case Summary Large) expanded or collapsed?
Edit:
Here are the meta tags in use,
<meta property="og:title" content="**masked**"/>
<meta property="og:description" content="**masked**" />
<meta property="og:image" content="**masked**" />
<meta property="twitter:card" content="summary_large_image" />
<meta property="twitter:image:src" content="**masked**" />
<meta property='twitter:site' content='**masked**'/>
(I am currently not using twitter:title and twitter:description since those are being read by twitter from the OpenGraph equivalent tags used.)
Take a look at this discussion. This is the expected behavior of Twitter cards (sadly).
If you want to show it by default, the tweet has to be either promoted or the image has to be hosted on Twitter's site (if it's hosted on a third party website, it will not show by default).