A visitor takes pictures with a smartphone of an artwork entitled “Blue Europe, 2015” by Chinese artist Liu Bolin, on display during the exhibition “Visible Invisible” at the Mudec Museum in Milan on May 14, 2019. Liu Bolin known as “the invisible man” for his photographic self-portraits, focused on a body-painting blending with the surrounding area. (Photo by Miguel Medina/AFP Photo)

US actress, model and transgender activist Leyna Bloom poses during a photocall for the film “Port Authority” at the 72nd edition of the Cannes Film Festival in Cannes, southern France, on May 19, 2019. (Photo by Stephane Mahe/Reuters)

Russian police cadets march during general rehearsal of the Victory Day parade on the Dvortsovaya Square in St. Petersburg, Russia, 07 May 2021. The military parade marking the 76th anniversary of the victory over Nazi Germany in the World War II will take place on the Dvortsovaya Square on 09 May 2021. (Photo by Anatoly Maltsev/EPA/EFE)

An Israeli police officer holds his weapon as he stands in front of an injured Israeli driver moments after witnesses said his car crashed into a Palestinian on a pavement during stone-throwing clashes near Lion's Gate just outside Jerusalem's Old City on May 10, 2021. (Photo by Ilan Rosenberg/Reuters)

These friends took a tumble after sharing a hug in Leeds in northern England on May 17, 2021, as Covid-19 lockdown restrictions ease. (Photo by London News Pictures)

A model rehearses with a fabric face mask on, designed by Zhou Li for her Autumn/Winter 2020 collection show, during China Fashion Week in Beijing, following the novel coronavirus disease (COVID-19) outbreak, China on May 3, 2020. (Photo by Tingshu Wang/Reuters)

Riot police wear face masks, as a precautionary measure against the COVID-19 coronavirus, allow a women to cross a cordon after a protest by pro-democracy demonstrators at a shopping mall in Hong Kong on May 9, 2020. (Photo by Isaac Lawrence/AFP Photo)

Health authority workers sanitise the rural community of Teocelo, Veracruz, Mexico on May 12, 2020 – in the hope of preventing the spread of COVID-19 infections. (Photo by Hector Adolfo Quintanar Perez/ZUMA Wire/Rex Features/Shutterstock)