<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/24202267/w%3D160_h%3D160_s%3D1/4fcb426453ecc0411c3f233f5e5e9e3c>
<https://marketplace.500px.com/photos/24202267/almost-blue-by-kenny-barker>