Apparently it is good luck to touch the right-hand bronze plaque, showing the saint being chucked into the river. A lot of people seem to have misunderstood this and touch the left-hand plaque instead, showing a soldier with a dog!

A fair degree of patience is required for this kind of shot. You have to be prepared to wait a few minutes until an opening offers up in cattle-horde of tourists streaming by, then snap two-three photos before more people stampede through your field of view!