hmm...
so it is justified to make fun if there is no 'explanation' about the photo?
anyway...
this a multitemporal image. afaik; commonly used in GIS / satellite mapping.
a composite of 3 b&w images taken at same place at different time.
objects that are not moving in those 3 images, are rendered in b&w,
those which are moving, are rendered in colour.
further explanation can be found at Bjorn Rorslett website
http://www.naturfotograf.com