A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

Mary McHugh mourns her slain fiance Sgt. James Regan at “Section 60” of the Arlington National Cemetery May 27, 2007. Regan, a US Army Ranger, was killed by an IED explosion in Iraq. (Photo by John Moore/Getty Images)

Television actress Catherine Fuller visits Trafalgar Square in London and feeds the famous pigeons. (Photo by Harry Kerr/BIPs/Getty Images). 26th June 1956

Women wearing face-kini masks lie on a beach to rest in Qingdao, Shandong province, China, June 3, 2015. A pale complexion is highly prized as delicate and feminine in China while dark skin suggests tanning caused by farming the fields or other lowly, outdoor work. (Photo by Reuters/Stringer)

Russian pop art photographer Sergey Chilikov captures a nation liberated from the social oppression of late-era Soviet rule – at parties, in the streets, and bouncing high. His exhibition, Photoprovocations, will be at Photo London, 19-22 May. Here: Yoshkar-Ola, Matrosova Street (1995). (Photo by Sergey Chilikov)

A farmer rides a truck in a village near Nong Khai, Thailand, September 16, 2015. (Photo by Jorge Silva/Reuters)

Atmosphere at the 84th Annual Hollywood Christmas Parade held at The Roosevelt Hotel on November 29, 2015 in Hollywood, California. (Photo by Zuma Wire/Rex Shutterstock)

A girl carries on her head a pile of dried shrubs she gathered for cooking and heating, in Kabul, Afghanistan November 18, 2015. (Photo by Omar Sobhani/Reuters)