An employee walks by an art work entitled ‘Ace, 1962’ by US artist Robert Rauschenberg during a press preview at the Tate Modern in London on November 29, 2016. / AFP / Daniel LEAL-OLIVAS / RESTRICTED TO EDITORIAL USE – MANDATORY MENTION OF THE ARTIST UPON PUBLICATION – TO ILLUSTRATE THE EVENT AS SPECIFIED IN THE CAPTION (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)