They didn't use a dropcloth while painting the building a light color.

So the sidewalk was spattered some time later with little drops of white-yellow paing, and one bigger spill about the size of a dinner plate.

The bigger spill had lines in it from dirt filling in wrinkles in the dried paint. Someone with a Magic Marker used four or five more lines to make the blob a portrait of William Shakespeare.

In a way, it's all an invitation to dance; it's a matter of hearing it.