Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

A model presents a creation at the Sophia Webster presentation during London Fashion Week in London, Britain February 20, 2017. (Photo by Neil Hall/Reuters)

Emma Watson poses at the winners boards at the Sony Ericsson Empire Film Awards at the Grosvenor House Hotel on March 9, 2008 in London England. (Photo by Dan Kitwood/Getty Images)

A child plays with a soap bubble on the city hall plaza on March 14, 2015 in Paris. (Photo by Dominique Faget/AFP Photo)

Artists from Cirque Du Soleil: Totem perform at Royal Albert Hall on January 4, 2012 in London, England. (Photo by Danny Martindale/Getty Images)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

A man arranges a display of cacti during preparations for the RHS Chelsea Flower Show in London, Britain May 21, 2016. (Photo by Neil Hall/Reuters)

A model presents a creation at the Nasir Mazhar catwalk show at London Collections Men in London, Britain June 11, 2016. (Photo by Neil Hall/Reuters)