Workers sleep on a railway track under repair in New Delhi, India, June 15, 2018. (Photo by Saumya Khandelwal/Reuters)

Participants in costumes pose before a Halloween parade in Kawasaki, south of Tokyo, Japan on October 28, 2018. (Photo by Toru Hanai/Reuters)

Guanacos sit during a signing ceremony in Patagonia Park, Chile, January 29, 2018. Chilean President Michelle Bachelet signed decrees Monday creating vast new national parks using lands donated by U.S. conservation organization Tompkins Conservation in what is believed to be the largest private donation of land ever from a private entity to a country. (Photo by Esteban Felix/AP Photo)

A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)

Pumpkins and a mock up skull are seen ahead of Halloween at Wilmersdorfer Strasse shopping street, as the coronavirus disease (COVID-19) outbreak continues, in Berlin, Germany, October 26, 2020. (Photo by Fabrizio Bensch/Reuters)

A woman takes pictures as Britain driver Lewis Hamilton steers his Mercedes during the third free practice at the Monaco racetrack, in Monaco, Saturday, May 26, 2018. The Formula one race will be held on Sunday. (Photo by Luca Bruno/AP Photo)

A woman sits as she gets a tattoo on her leg during the annual Panama City Ink Fest in Panama City August 16, 2015. (Photo by Carlos Jasso/Reuters)

“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)