<http://schema.org/thumbnailUrl>
<https://drscdn.500px.org/photo/12891755/w%3D160_h%3D160_s%3D1/4fd2bcbd66d80582d056e6d1f93064c3>
<https://marketplace.500px.com/photos/12891755/sandringham-house-norfolk-by-mike-howe>