<http://schema.org/keywords>
"Animal, Animal Themes, Animals In The Wild, Aquatic, Exhaustion, Eyes Closed, Nature, One Animal, Swan, Tranquility, White, Wildlife"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/16363905/sleepy-swan-by-daniel-wewerka>