<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/7670312/w%3D160_h%3D160_s%3D1/f8a1b6bc0b3ace7fd53c10c8ff4cced1>
<https://marketplace.500px.com/photos/7670312/home-flowers-02-by-vlado-ferencic>