The Five-Second Rule

The scene opens up with an aerial view of a nice park.  A walks along a seemingly clean sidewalk while munching on a cookie, but then drops it.  He stares at it wistfully for a while and after making furtive sideways glances, quickly picks it up and eats it.  The scene rewinds to about 10 minutes before this occurrence.  A snail is slowly oozing along the same sidewalk, leaving behind a slimy trail.  Suddenly, it is crushed flat by a dirty, bare foot. The foot belongs to a dirty homeless man who is walking across the sidewalk.  We return our focus to the messy remains of the snail.  A dog's nose enters the scene, soon followed by the his eager face as he licks up the slimy snail remains.  He sits panting happily when suddenly, his expression changes to that of extreme discomfort.  The dog poos (not shown) and its owner snaps on his glove for the implied clean-up.  The dog trots away, and we watch as the faint remains of the dog's mess fade away overnight (time lapse), leaving no trace of it behind.  The clip ends with the opening scene when the man drops a cookie on that spot.
After the credits, a different man drops a bagel on the same spot (cream side down) and his eyes dart left and right as he checks to see that no one is watching....(Not shown in reel).