<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/11783709/w%3D160_h%3D160_s%3D1/b4cd2e1ada09ab666d20c5da63af424b>
<https://marketplace.500px.com/photos/11783709/nik-2168-by-mitch-aunger>