<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/19273363/w%3D160_h%3D160_s%3D1/e5c6ca7f8b6c5a659fef1fbfab647c0a>
<https://marketplace.500px.com/photos/19273363/painted-sunrise-by-brian-behling>