Nellie, Anne of Cleves is buried on the South side of the Sanctuary, where the Royal Gallery is constructed at each coronation.

Erection of this Gallery necessitates dismantling of the tomb. In your photograph, one can see where the vertical section has been taken out and the exposed slot in the pillar next to the Retable hasn't yet been made good. In 1953, Queen Elizabeth and Princess Margaret were literally sitting on top of Anne of Cleves (the body is under the floor) and her tomb wasn't returned until the autumn.

She was the only one of Henry's six wives to play his game - and get a comfortable and honoured life in return - so maybe she doesn't mind too much!