Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)

A hippopotamus walks across flooded street in Tbilisi, Georgia, June 14, 2015. (Photo by Beso Gulashvili/Reuters)

Sanyu (L), a five-day old Rothschild's Giraffe calf is nuzzled by another member of the herd in their enclosure at Chester Zoo, in Chester, Britain, in this June 12, 2015 file photo. (Photo by Phil Noble/Reuters)

People brave the cold and snow as they walk in the main pedestrian street of Istiklal in central Istanbul, in this February 17, 2015 file photo. (Photo by Murad Sezer/Reuters)

The sunset illuminates the peaks of the mountains near the Swiss mountain resort of St. Moritz, in this January 24, 2015 file photo. (Photo by Arnd Wiegmann/Reuters)

Arthur Ward stands with his Pyrenean Mountain Dog Cody during the first day of the Crufts Dog Show in Birmingham, central England, in this March 5, 2015 file photo. (Photo by Darren Staples/Reuters)

A widow daubed in colours takes part in Holi celebrations organised by non-governmental organisation Sulabh International at a widows' ashram at Vrindavan, in the northern Indian state of Uttar Pradesh, in this March 3, 2015 file photo. (Photo by Ahmad Masood/Reuters)

Smoke rises from Villarrica volcano as seen near the town of Pucon in southern Chile, in this June 23, 2015 file photo. (Photo by Andres Stapff/Reuters)

A man stands under an umbrella while photographing a snow storm in Times Square, New York, in this January 26, 2015 file photo. (Photo by Adrees Latif/Reuters)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, in this May 22, 2015 file photo. (Photo by Mohamed Nureldin Abdallah/Reuters)

Visitors walk past a train-shaped ice sculpture ahead of the 31st Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province, in this January 4, 2015 file photo. (Photo by Kim Kyung-Hoon/Reuters)

Smoke and ash rise from the Calbuco volcano as seen from the city of Puerto Montt, in this April 22, 2015 file photo. (Photo by Rafael Arenas/Reuters)

An aerial view of flower fields is seen near the Keukenhof park, also known as the Garden of Europe, in Lisse, The Netherlands, in this April 15, 2015 file photo. (Photo by Yves Herman/Reuters)

A tree is pictured in a blooming rapeseed field on a spring morning in Vufflens-la-Ville near Lausanne, in this April 23, 2015 file photo. (Photo by Denis Balibouse/Reuters)

Argentina's Lionel Messi falls in the net during the Copa America 2015 final soccer match against Chile at the National Stadium in Santiago, Chile, in this July 4, 2015 file photo. (Photo by Ivan Alvarado/Reuters)

A cow stands in the middle of a busy road as auto-rickshaws pass by in Bengaluru, India, in this June 2, 2015 file photo. (Photo by Abhishek N. Chinnappa/Reuters)

An aerial view shows the Mont Saint-Michel off France's Normandy coast, in this March 20, 2015 file photo. (Photo by Pascal Rossignol/Reuters)

Cats crowd the harbour on Aoshima Island in the Ehime prefecture in southern Japan, in this February 25, 2015 file photo. This picture was third most popular. (Photo by Thomas Peter/Reuters)

Benny Wasserman, 81, (C) stands with other people dressed as Albert Einstein as they gather to establish a Guinness world record for the largest Einstein gathering, to raise money for School on Wheels and homeless children's education, in Los Angeles, California, United States, in this June 27, 2015 file photo. This picture was second most popular. (Photo by Lucy Nicholson/Reuters)

The White House is illuminated in rainbow colors after today's historic Supreme Court ruling legalizing gay marriage in Washington, in this June 26, 2015 file photo. This picture is the most popular. (Photo by Gary Cameron/Reuters)