In 1994, after the fall of the Soviet Union, all Ukrainians had to get a new passport – and photographer Alexander Chekmenev was on hand to take their photos. The snatched extra shots he took are remarkable in their honesty and tenderness. (Photo by Alexander Chekmenev/The Guardian)

A woman walks through flood water during heavy downpour at a street in Genoa, Italy, 10 October 2014. At least one person died due to flooding after heavy rains caused the Bisagno river, which runs through Genoa city to overflow. Part of the city was in black-out with flooded streets and parked cars dragged away by the water's force. (Photo by Luca Zennaro/EPA)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

Actress Kerry Washington, Harvard University's Hasty Pudding Theatricals' Woman of the Year, throws wine in the face of an actor playing Republican presidential candidate Donald Trump, Thursday, January 28, 2016, as she is roasted in Cambridge, Mass. (Photo by Elise Amendola/AP Photo)

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)

It's often said that pets and their owners can start to look alike, but these adorable photographs take the old mantra to a new extreme. They are the work of Svetlana Valyiskaya (27), from St Petersburg, who snaps pets in everyday poses in her spare time from her job as a commercial photographer. The vibrant costumes and scenes, which Svetlana designs herself, have made the photos a hit in her native Russia – and it's not hard to see why. She said: “I really love animals, they are loyal, faithful and true and always interesting to work with – plus they never criticise the photographs afterwards”. (Photo by Svetlana Valyiskaya/Mercury)

Photographer Alexander Lepeshkin spends whole nights at Clumba parties, or costume parties where the young creatives of Russia put on their most flashy and drink. His photos capture candid moments of alcohol-enhanced connections and collapses, but he says he’s not a party photographer – he’s a youth photographer. Photo: A Loshadka party in St. Petersburg, 2010. (Photo by Alexander Lepeshkin)

Drastic inequality is by no means new in New York. Jacob A. Riis was called a muckraker after he chose to spotlight the city’s poverty at the turn of the 20th century by photographing it. Here: Sweatshop in Hester Street, 1889-1890. (Photo by Jacob A. Riis/Museum of the City of New York, Gift of Roger William Riis)