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

Students hold their weapons before the swearing in ceremony for the military students, in Bucharest, Romania, Wednesday, October 25, 2017. The Romanian Army is proudly celebrating their Army Day and marking 100-years since the landmark battle of Marasesti, a key World War I battle in 1917 when Romanian and Russian soldiers defeated German troops, halting a German offensive. (Photo by Vadim Ghirda/AP Photo)

An officer reviews members of the honor guard as they line up before a welcoming ceremony for visiting Mozambique's President Filipe Jacinto Nyusi at the Great Hall of the People in Beijing, Wednesday, May 18, 2016. (Photo by Mark Schiefelbein/AP Photo)

A street artist makes soap bubbles in front of the Alte Nikolaikirche church at the Roemerberg square in Frankfurt am Main, western Germany, on August 12, 2018. (Photo by Frank Rumpenhorst/DPA/AFP Photo)

Tuvalu Beneath the Rising Tide by Sean Gallagher, Tuvalu. Changing environments prize: Fallen trees lie on a beach as the waves from the Funafuti lagoon in Tuvalu lap around them. Land erosion has always been a problem for the South Pacific country but problems are intensifying as sea levels rise. Rising seas are on the verge of completely submerging the tiny archipelago’s islands. (Photo by Sean Gallagher/CIWEM Environmental Photographer of the Year 2019)

An owner poses with her Maine Coon cat in front of a mirror during a cat exhibition in Bishkek on April 19, 2015. Cat lovers from Kyrgyzstan, Kazakhstan and Uzbekistan took part in the exhibition. (Photo by Vyacheslav Oseledko/AFP Photo)

Visitors wear shirts with an image of former Chinese leader Mao Zedong at the Shanghai World Expo site in Shanghai, May 2, 2010. (Photo by Aly Song/Reuters)

Dancer Maithili Vijayakumar performs on the occasion of the launch of 2021 Diwali celebrations, at St. Andrew Square in Edinburgh, Scotland, Tuesday, November 16, 2021. The multi-cultural celebration will take place for the first time in two years in the center of Edinburgh on Sunday, Nov. 21. (Photo by Andrew Milligan/PA Wire via AP Photo)