HI,
I put it through the facebook debugger and got Object Debugger returns: “Error parsing input URL, no data was scrape”. It could be the theme I am using. The picture comes up on 2 blog posts but the 2 most recent i get the grey man. It might be the theme I am using. I set featured image and set the image in the top of the post. I have done a display:none on the main featured image because it looks pixelated.
https://snoopcreative.com/recent-google-changes-be-mobile-friendly/