<http://schema.org/image>
<http://rack.0.mshcdn.com/media/ZgkyMDEyLzEyLzA0LzcxL3N0dW1ibGV1cG9uLmNWMi5wbmcKcAl0aHVtYgkxMjAweDYyNyMKZQlqcGc/7ef18f5f/346/stumbleupon-s-new-explore-feature-lets-you-stumble-specific-topics-622056ded8.jpg>
<http://mashable.com/2011/08/17/stumbleupon-explore-box/>