title: No thumbnail shows on facebook, when I post a link to my site
body: <p>I just published a new website. When someone tries to publish the link on Facebook, no thumbnail-options shows up, even though there are plenty of image-files to choose from.</p>
  
  <p>When I post the link to the "gallery" section though, I get the option to choose a thumbnail from the images in the gallery only.</p>
  
  <p>The url to the website: <a href="http://www.ridderhest.no" rel="nofollow">http://www.ridderhest.no</a></p>