Image tested in validator, not shown in summary cards


#1

In most tweets from our account with links to our websites, we’ve implemented tags for the summary_large_image card. While the selected image is displayed when running the URL’s through the Card Validator, almost no image is shown when the tweet is opened in a browser or on the Twitter app.

For example
Shared link: https://www.iwink.nl/kennis-inspiratie/strategie/hoe-smart-is-uw-website
Tweet: https://twitter.com/iWink/status/567611160112160768

I’m a bit confused as the validator does show the image. Did I overlook something?