In the signs mesh, an image consisting of NXN signs is created. Each sign has its own mesh, with the specific sign being the central point in the mesh, while the other signs revolve around the central sign by their distance from the central sign.
Considering the fact that new signs are added to the site every day, the picture you see is valid only for that day. Also note that if you move to the Hebrew version of the site the resulting image will be a "mirror image" of the current image, because of the different direction in which the other signs revolve around the central sign.
Clicking on each of the signs that constitute the signs mesh, will generate a new mesh around the clicked sign.