It was a moment that was as pregnant with significance as it was fleeting. I was chairing a discussion at Art Dubai, the second edition of the city’s art fair, when one of my guests, Beatrix Ruf, director of Zürich’s Kunsthalle, showed a slide of a number of images, one of which appeared to be blank. She made a brief allusion to a work she had “meant to show”, and moved on.

What I knew, because she had told me about it beforehand, was that the blank space had been an image of a nude body, which was quietly removed by the organisers for fear that it would cause offence.