A man smokes marijuana during a demonstration in support of the legalization of marijuana in Medellin, May 2, 2015. (Photo by Fredy Builes/Reuters)

Sumo wrestlers compete during the “Honozumo” ceremonial sumo tournament at the Yasukuni Shrine in Tokyo April 3, 2015. (Photo by Thomas Peter/Reuters)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

A contestant poses for a photograph backstage ahead of the Miss Gay Jozi pageant in Johannesburg, May 23, 2015. (Photo by Siphiwe Sibeko/Reuters)

A worker stack bricks on his head at a brick factory in Lalitpur January 12, 2015. (Photo by Navesh Chitrakar/Reuters)

An incredible clear-air lightning display from storms to the east of Noonamah, just outside Darwin on April 6, 2015. (Photo by Jacci Ingham/The Guardian)

Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)

Demonstrators hold masks depicting Colombian citizen Mile Virginia, who was murdered along with photojournalist Ruben Espinosa and three other women, during a protest in Mexico City, August 16, 2015. Espinosa, a prominent Mexican news photographer was among five people found dead in a middle-class neighborhood of the capital on July 31, 2015. Espinosa, who worked for the weekly magazine Proceso and the photo agency Cuartoscuro, had sought shelter in Mexico City earlier this summer saying he had been followed and threatened in the eastern state of Veracruz. (Photo by Tomas Bravo/Reuters)