<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/25694171/w%3D160_h%3D160_s%3D1/f64ff8766bf7540cdbc7c239c1b3cf6b>
<https://marketplace.500px.com/photos/25694171/we-re-watching-you-by-cedric-jean-marie>