We might have foreseen that the movement to radicalise the art and museum world would in time come back to bite its own children. It has happened more quickly than we thought, as witness seriously red faces at the National Portrait Gallery (NPG) last week.

Among the paintings on display at the NPG was one by French society artist James Tissot of Edward Fox-White, a well-known British 19th century art dealer who opened his first gallery in Glasgow in 1854.