My honest first reaction was "is that one of those optical illusions where you can see more than thing (like below - one image mildly NSFW). But once I got past that it made me think of being aware of water usage/water waste.
It also made me think you were cheap for stealing an image off of
iStockphoto.com 
ETA: Oh... there's an actual poll in this thread. Sorry: missed it the first time around.