Vivian Odhiambo, 24, frys samosas in the trading centre of Kogelo, west of Kenya's capital Nairobi, July 14, 2015. Odhiambo said, “Obama is our hero and we wait to welcome him back home again. We in Kogelo have witnessed general growth and we are proud of being associated with the Obamas”, she added. As U.S. President Barack Obama visits Kenya, a personal connection to his father's birthplace of Kogelo dominates a trip that Kenyans view as a native son returning home. Residents from a herdsman to a housewife share their views on what Obama has achieved and what they would like to see next. (Photo by Thomas Mukoya/Reuters)

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

Hikaru Cho believes that we should challenge our imaginations to create new work using traditional tools, not fancy computers and software. (Photo by Jim Marks/PA Wire)

People don’t realize how much our exterior can affect our mood. If we make ourselves smile, we might feel a little better, yet if we frown, we soon get the irresistible urge to listen to Blues and weep over the days long gone. The same goes for our clothing. Many people, especially the elderly, tend to dress in the same old rags, without ever feeling the need to change something about their appearance. However, as Cue Qozop clearly demonstrates in his Spring – Autumn photoset, clothes can completely alter the appearance and the mood of the wearer. Elderly people dressed in young people’s clothes look much younger and happier. They look as if they are full of vigor and are about to set out on an amazing adventure.

California-based photographer Seth Casteel made his name taking photographs of dogs underwater, but before that, he was snapping cats on land.

Professional conceptual category winner. Greetings from Mars, by Julien Mauve, France. Mauve says: “I have always wondered what it would be like to discover a totally different world ... and to photograph it for the first time as if I was Ansel Adams. So I came up with this project, which is about space exploration and discovery. But it’s also about our behavior in front of landscapes and how we create pictures that will share our personal story with the world”. (Photo by Julien Mauve)