The meaning is a Luca’s idea.
A sign that cannot be explained, it isn’t a useful thing to do. That’s it, he told me.
His way to interpret the “Iazzo dello Scagno” made him realize this sign. He’s so young! He’s only 20. Here are the walls, built as for protection for animals, becoming concentric curves, closed around an invisible center that wrap around and shelter.
I haven’t already asked him anything, maybe I won’t. But I’m sure he’s able to see something in the middle of the spiral.