What makes pics of your feet / toes out and about so popular? Maybe its the idea of capturing what you see. Perhaps it is the fit for reproduction without much effort on modification. We might also be attracted to the ability of photos (albums) to freeze a place and moment in time.

 
cobblestones and walking shoes
stone stairs and sandals
dry earth and sneakers
stained wooden floor and leather shoes
path in a forest and walking shoes
grass and flip-flops