Hi there,
I noticed that your site (paleoandmeblog.wordpress.com) is hosted over at WordPress.com while these forums are intended folk who are hosted elsewhere and running on the free software available here at www.ads-software.com.
The difference between the two types of WordPress (WordPress.com and www.ads-software.com) is a common and understandable point of confusion. If you’re unsure, then I recommend the following overview:
https://en.support.wordpress.com/com-vs-org/
With the above in mind, please post to the Themes forum on WordPress.com with any extra questions you may have:
https://en.forums.wordpress.com/forum/themes
In answer to your question: WordPress.com sends recommendations out to Facebook for the thumbnail based on the specific page you’re sharing. Facebook also have some specific requirements that images need to meet. You can read more details on these recommendations and requirements here:
https://en.support.wordpress.com/facebook-image-thumbnail/
If, based on the above, you believe that an image on your site should be displaying as a thumbnail on Facebook’s end, then try entering the URL into Facebook’s debug tool:
https://developers.facebook.com/tools/debug/sharing
You can then choose the option to “Scrape Again,” which may be enough to get the correct thumbnail to display.
If that doesn’t help, please post to the forum on WordPress.com with details of the specific posts/pages on your site that are displaying an incorrect thumbnail.
Thanks!
