In urban places, human consumers are highly prone to spilling their sugar drinks (which they must carry around with them at all hours), and so the end result is that pavements and sidewalks become spattered with sticky, tarry liquids which collect dust, effectively darkening these spots so that they contrast nicely with the cement. It is then that these involuntary paintings sometimes have a story to tell, should the splatter marks so happen to resemble something familiar enough for the psyche to latch onto. As can be seen from the following images, patterns emerge sometimes.
Some of these images were made by duplicating part of the photo symmetrically along a central axis.