Image in shared post on FB

I've been playing around with the facebook object debugger to see how certain pages of my dolphin 7.2 site appear when being shared. One thing I noticed is the image facebook selects is either super random or nothing at all is displayed, which makes the shared content look rather boring.

 

Does anyone know how to have a default image always be displayed when pages are shared?

 

https://developers.facebook.com/tools/debug/og/object/

Quote · 18 Feb 2016
 
 
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