Our eyes have been considered as the windows to the soul.While clicking a picture,we often focus on a subject's eyes.We have such images of eyes which will make you think of fantasy world filled with fairies.
In this image, the blur of people moving around in the crowd makes it look interesting, but it is also focusing on particular people who are standing, walking, moving in what looks like a busy area. A slow shutter speed is used in this image.
Nagai Hideyuki uses two sketchbooks to create illusions. I was thinking this may be possible to do on the street/buildings with chalk, but in order to view it correctly everyone would have to be the same height, so that probably wouldn't work.