When I post to Facebook, my header logo appears as a thumbnail. The image has the wrong shape and size to function that way. I have an older version (much smaller 180x180) logo that I used to use which could work nicely as a thumbnail for Facebook posts. I don't want to use it as the header logo.
How can I make this the "featured" image as far as Facebook is concerned while continuing to use my existing header image?
By "Featured," I do NOT mean that I want this image to be displayed in the page. I only want it as the default thumbnail image for things like Facebook posts, etc.
Thanks.
website: http://www.scripturequizzer.com
thumbnail: http://www.scripturequizzer.com/wp-content/uploads/2014/07/scripturequizzer-180x180.png