As the passagiata was waning, I put my camera down on the pavement and took a time-exposure of about 7 seconds. People passed by during the exposure, and you can see slight vestiges of their presence -- look for some ghostly disconnected feet. Their feet remained still just long enough to register slightly on the image while the rest of their bodies did not register (save for a swirling scarf!). But notice the couple looking at the poster; they didn't move a muscle for the entire duration!