In the middle we have a tomb, on the right we have monks, on the left we have prominent laymen; one of the monks carries a money bag, another holds a glove, some of the laymen carry things that look like symbols of authority. I have no idea what it all means. It could be a monkish legend, it could be an incident in the history of the cathedral. It looks as if the lid of the tomb is being opened but that's probably just an effect of the artist's wonky grasp of perspective.