The Temple of Heaven (The Qi Nian Temple) is illuminated as Beijing celebrates the New Year's Eve at the Temple of Heaven Park on December 31, 2011 in Beijing, China. (Photo by Lintao Zhang/Getty Images)

After some days with temperatures below freezing point, I was out skating at some lakes at the outskirts of Oslo in Norway. After a while I noticed something on the ice. To my astonishment it was a dead frozen frog.

Sandrine Kerfante has had a fascination with “doubles” ever since meeting her mother’s twin as a child. In 2012, this lifelong captivation inspired her to create a blog called twin-niwt, which celebrates photographs of doubles in all their forms. “I’m fascinated by the idea of the duo, repetition, symmetry, reflection, mirror games and all the symbolism associated with it”, she says. “I think it’s a topic often present in photography, more or less consciously”. (Photo by Sandrine Kerfante/The Guardian)

Revellers attend the Victorian Picnic during the Wave and Goth festival in Leipzig, Germany, May 22, 2015. The annual festival, known in Germany as Wave-Gotik Treffen (WGT), features over 100 bands and artists in venues all over the city playing Gothic rock and other styles of the dark wave music subculture. One of the biggest of its kind, the event attracts a regular audience of up to 20,000, the organisers said. (Photo by Hannibal Hanschke/Reuters)

Festival-goers wash on Shipyard Island, the venue of the 24th Sziget (Island) Festival in Northern Budapest, Hungary, 15 August 2016. The venue, one of the biggest cultural events of Europe, offers art exhibitions, theatrical and circus performances and above all music concerts from 10 to 17 August. (Photo by Szabó Gábor/Origo.hu)

Actress Bai Ling poses for a picture in front of St. Basil's Cathedral at the Red Square in Moscow, Russia, July 1, 2015. (Photo by Ivan Burnyashev/Reuters)

A rickshaw driver looks out the windshield as he drives onto the highway in Mardan, Pakistan January 30, 2017. (Photo by Fayaz Aziz/Reuters)