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

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.)

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)

Elijah Wood poses for a tintype (wet collodion) portrait at The Collective and Gibson Lounge Powered by CEG, during the 2014 Sundance Film Festival in Park City, Utah. (Photo by Victoria Will/AP Photo/Invision)

Linda Cerruti of Italy competes in the Synchronized Swimming Solo Tech preliminary round during Day Two of the 14th FINA World Championships at the Oriental Sports Center on July 17, 2011 in Shanghai, China. (Photo by Ezra Shaw/Getty Images)

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)

Models walk the runway during the Maison Margiela Spring Summer 2016 show as part of Paris Fashion Week on January 27, 2016 in Paris, France. (Photo by Francois Durand/Getty Images)