A painting of Chinese President Xi Jinping holding an umbrella is seen on the toilet wall in a guesthouse in Hong Kong December 30, 2014. Set up in a small apartment in the Causeway Bay shopping district, the guesthouse that gives what it calls “Umbrella Revolution Occupation Experience” charges guest HK$100 (US$13) a night to stay in a tent surrounded by pro-democracy banners, a cardboard cutout of President Xi Jinping holding a yellow umbrella, and serve toilet paper printed with the face of embattled leader of Hong Kong chief executive Leung Chun-ying. (Photo by Tyrone Siu/Reuters)

Nic Smith poses to show her body art during the 10th International Tattoo Convention in London September 27, 2014. (Photo by Neil Hall/Reuters)

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)

Aurora Australis from Beerbarrel Beach, by James Stone. Runner Up: Aurorae. (Photo by James Stone/Astronomy Photographer of the Year)

Toure, a Gambian salt harvester, holds a basket filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by Marco Longari/AFP Photo)

Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

Young category winner. Great autumn morning by Fabian Dalpiaz. (Photo by Fabian Dalpiaz/2018 Astronomy Photographer of the Year)

Men slicing blubber off a large, dead whale. (Photo by Topical Press Agency/Getty Images). Circa 1912