Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

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)

The Virgin of El Rocio is carried by pilgrims during a procession around the shrine of El Rocio in Almonte, southern Spain, May 25, 2015. Every spring hundreds of thousands of devotees converge at a shrine to pay homage to the Virgin del Rocio during an annual pilgrimage which combines religious fervour and festive colour. (Photo by Marcelo del Pozo/Reuters)

Workers attach a hat to a pinata depicting the drug lord Joaquin “El Chapo” Guzman at a workshop in Reynosa, July 21, 2015. Guzman broke out of Mexico's top maximum security prison through a tunnel built into his cell earlier this month. (Photo by Daniel Becerril/Reuters)

Pilgrims rest on June 6, 2019 in Villamanrique, during a pilgrimage to the village of El Rocio. El Rocio pilgrimage, the largest in Spain, gathers hundreds of thousands of devotees in traditional outfits converging in a burst of colour as they make their way on horseback and on board decorated carriages across the Andalusian countryside. (Photo by Cristina Quicler/AFP Photo)

A hummingbird flies in the sanctuary “El Paraiso de los Colibries” near Cali, Colombia, July 28, 2016. (Photo by Jaime Saldarriaga/Reuters)

An Acehnese female police officer wear a hijab on duty in the street in Banda Aceh, Indonesia, 27 March 2015. Indonesia National Police officially issued a regulation allowing female police officer to wear the Islamic hijab (heads craft) as a part of their uniform. Indonesia is the biggest Muslim population in the world. (Photo by Hotli Simanjuntak/EPA)

A Catholic faithful holds a figurine of baby Jesus during a religious procession on Holy Innocents Day in Antiguo Cuscatlan, on the outskirts of San Salvador, December 28, 2014. Festivities are held every December 28 in honor of children, termed the Holy Innocents, below the age of two who were ordered to be killed by King Herod, according to biblical passages. (Photo by Jose Cabezas/Reuters)