Figure Skating, ISU Grand Prix of Figure Skating NHK Trophy 2016/2017, Ice Dance Short Dance, Sapporo, Japan on November 26, 2016. Kaitlin Hawayek and Jean-Luc Baker of the U.S. compete. (Photo by Issei Kato/Reuters)

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

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Figure Skating, ISU Grand Prix Rostelecom Cup 2016/2017, Ice Dance Short Dance, Moscow, Russia on November 4, 2016. Kaitlyn Weaver and Andrew Poje of Canada compete. (Photo by Grigory Dukor/Reuters)

American model and television personality Kendall Jenner attends the Tiffany & Co. Paper Flowers event and Believe In Dreams campaign launch on May 3, 2018 in New York City. (Photo by Jamie McCarthy/Getty Images for Tiffany & Co.)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)

An African giant pouched rat sniffs for traces of landmine explosives at APOPO's training facility in Morogoro on June 17, 2016. APOPO trains the rats to detect both tuberculosis and landmines at its facility. Every year landmines kill or maim thousands of people worldwide. The trained rats sniff for explosive and so are able to detect the presence of landmines far faster than conventional methods which involve metal detection. (Photo by Carl De Souza/AFP Photo)

2016 Rio Olympics, Gymnastics training, Rio Olympic Arena, Rio de Janeiro, Brazil on August 4, 2016. Close up of the feet of Rebecca Downie (GBR) of United Kingdom as she trains on the beam. (Photo by Dylan Martinez/Reuters)