“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Soldiers on exercise in Kenya. The image, by Sergeant Dek Traylor, is among the section winners in the UK Army Photographic Competition 2018. (Photo by Sergeant Dek Traylor/PA Wire Press Association)

Residents of the Santa Marta favela, Botafogo, south zone in Rio de Janeiro, Brazil unite to sanitize the community and fight the advance of the new coronavirus this Saturday, November 28, 2020. (Photo by Ellan Lustosa/ZUMA Wire/Rex Features/Shutterstock)

People without face masks are seen at Times Square during the coronavirus disease (COVID-19) pandemic in New York City, U.S., March 11, 2021. (Photo by Eduardo Munoz/Reuters)

A reconstruction of the first Neanderthal in the Netherlands, nicknamed Krijn, is on display in the National Museum of Antiquities in Leiden, The Netherlands, 06 September 2021. Krijn's face has been worked on for years by the brothers Adrie and Alfons Kennis. (Photo by Bart Maat/EPA/EFE)

Sabrina Crespo da Silva removes electrical tape from a client at her Sabrina Bronze rooftop salon, where she offers the service of taping on bikini tops which create crisp tan lines, in the Turano favela of Rio de Janeiro, Brazil, Thursday, January 27, 2022. Even though beaches reopened amid the COVID-19 pandemic, some clients using Sabrina's rooftop service say they are still anxious about returning to the crowded seashore and potentially catching the virus. (Photo by Silvia Izquierdo/AP Photo)

This picture taken on June 25, 2019 shows couples wait for their turn for their pre-wedding photo shoot at the Love Story in Rome Studio in Beijing. Increasingly elaborate pre-wedding photos are a booming industry in China, as young couples spend time and cash lining up glamorous photo shoots to display on their big day. (Photo by Fred Dufour/AFP Photo)