Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

As a social experiment, journalist Esther Honig contacted Photoshop artists across the world and told them to make her beautiful, and they did. Honigh said she was surprised by how her image was altered, saying the process has greatly changed her perception of beauty. Photo: “Before & After” project: Greece. (Photo by Esther Honig)

Children exercise before a wrestling practice session at an old Basque ball game gymnasium in downtown Havana, October 30, 2014. (Photo by Alexandre Meneghini/Reuters)

Models get ready backstage before the presentation of the Etam Live Show Lingerie at the Fashion Week in Paris, France, September 27, 2016. (Photo by Charles Platiau/Reuters)

Runners sleep before competing in the 2016 New York City Marathon in the Manhattan borough of New York City, NY, U.S. November 6, 2016. (Photo by Eduardo Munoz/Reuters)

A combination picture shows Aleppo's Umayyad mosque, Syria, before it was damaged on March 12, 2009 (top) and after it was damaged (bottom) December 13, 2016. (Photo by Omar Sanadiki/Reuters)

Beauty contestants prepare backstage before the fashion show of Miss Tiffany's Universe 2016 transvestite contest in Bangkok, Thailand, April 20, 2016. (Photo by Athit Perawongmetha/Reuters)