Leg rubbed out?

Today we (my son and I) spent many hours hanging our paintings in an old storehouse for iron, built in 1746, which nowadays is used as an art gallery with four planes.

The blip of today is Pontus standing on a stool fixing the lighting for the paintings, while a sun reflection from an opening in one of the old wooden shutters in the room, seem to have rubbed out some of his left ankle!