Girls rest on stairs at the China Digital Entertainment Expo and Conference (ChinaJoy) in Shanghai, China July 27, 2017. (Photo by Aly Song/Reuters)

Artist German Vinogradov acts in the performance of the burning of installation, devoted to Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, in the village of Nikola-Lenivets, Kaluga region, Russia, February 17, 2018. (Photo by Maxim Shemetov/Reuters)

Facade of the “Porcelain House”, built by Chinese collector Zhang Lianzhi, on November 1, 2008 in the Heping district of Tianjin, China. Over 400 million porcelain fragments, 5,000 ancient vases, 4,000 antique china dishes and bowls, over 20 tons of crystalline rocks and agate, 400 white marble stone carvings were incorporated in the five year refurbishment of the unique French styled house. (Photo by China Photos/Getty Images)

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)

Activists attend a parade to demand rights of gender equality to LGBT community members in Santiago, Chile, November 25, 2017. (Photo by Ivan Alvarado/Reuters)