Right now, I can upload an image that will act as the social media share image. (WordPress users will recognize this as the "Featured image") The social media share image can be uploaded here: Website > [page] > Settings > Social media > Thumbnail image for Facebook, etc. Now, once this image is there, it cannot be deleted, only replaced. If you don't want an image there, you must delete the page, instead, and start over. Very inconvenient if you're doing this to a page with a ton of subpages, which will all need to be moved over to the new page prior to deleting the old page.