A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)

A model presents a creation at the Central St Martin's catwalk show during London Fashion Week in London, Britain February 17, 2017. (Photo by Neil Hall/Reuters)

An Iraqi girl walks past a donkey-drawn cart carrying bricks at a brick factory near the central Iraqi shrine city of Najaf on May 16, 2017. (Photo by Haidar Hamdani/AFP Photo)

A Tibetan pilgrim prostrates herself at the Jokhang Temple in central Lhasa, Tibet Autonomous Region, China early November 20, 2015. Every day thousands of Tibetans visit and pray at Jokhang Temple, considered one of the most sacred places of worship. (Photo by Damir Sagolj/Reuters)

A dog walks past a mural by street artist Alex Martinez outside a shop which sells bags at Psiri area, central Athens, on Thursday, January 25, 2018. (Photo by Petros Giannakouris/AP Photo)

A participant wearing a costume poses for members of the public before the 40th anniversary of the Sydney Gay and Lesbian Mardi Gras Parade in central Sydney, Australia, March 3, 2018. (Photo by David Gray/Reuters)

The buildings of the banking district are seen through thousands of rain drops on a glass railing in central Frankfurt, Germany, Wednesday, January 11, 2017. (Photo by Michael Probst/AP Photo)