Twitter is displaying the wrong card for given URL’s, but they redirect to the correct URL.
Example:
Tweet: https://twitter.com/swimswamnews/status/772600296388358144
Card on Twitter: 
Article URL: https://swimswam.com/calvyn-justus-gets-olympicink-plus-lion-clubs-video/
Twitter Metadata on the page:
<meta name="twitter:card" content="summary_large_image"/>
<meta name="twitter:description" content="Swimming South Africa’s Calvyn Justus is our sport’s resident Youtube vlogger, with over 45,000 subscribers and nearly 3 million views, and we..."/>
<meta name="twitter:title" content="Calvyn Justus Gets His #OlympicInk, Plus Lion Clubs! (Video)"/>
<meta name="twitter:site" content="@swimswamnews"/>
<meta name="twitter:image" content="https://cdn.swimswam.com/wp-content/uploads/2016/09/Screen-Shot-2016-09-04-at-10.31.25-AM.png"/>
<meta name="twitter:creator" content="@HannahHecht"/>