I'm trying to implement a simple Facebook Share Dialog with Facebooks own JavaScriptSDK. So far I built a little WebApp with a working share Button that calls:

FB.ui({
  method: 'share',
  href: 'https://developers.facebook.com/docs/',
}, function(response){});

As I was trying different hrefs at one point, I sent an empty href resulting in this message: Error Message

But I can't seem to find anything about this "media" parameter in the documentation of facebooks share dialog. Is this a "legacy" parameter? Or could it be used to load image data into the preview of the share dialog?