Trafalgar Square piece by Mexican artist Teresa Margolles is made of masks depicting faces of transgender and non-binary people

A towering cuboid made of more than 300 masks depicting the faces of transgender and non-binary people, this year’s fourth plinth artwork, has been described as a piece designed to “unite the trans community around the world”.

The Mexican artist Teresa Margolles was flanked by members of her country’s trans community as Mil Veces un Instante (A Thousand Times in an Instant) was unwrapped in Trafalgar Square on Wednesday.