<https://spiderworking.com/wp-content/uploads/2012/11/twitter-link-thumbnail-1.jpg#primaryimage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/ImageObject>
<https://spiderworking.com/blog/2012/11/26/add-twitter-cards-to-your-wordpress-org-blog-with-yoast-cool-tool/twitter-link-thumbnail-2/>