Lots of funny shots in this challenge. For impact, i think you could happily have cropped to remove the cistern and the handle - they're not needed for the joke (the paper roll is enough), and then you'd have the dynamic moment of the shot - the finger graping at the paper - in a much stronger point of frame. I'm no fan of set-up stuff, but with clean composition, and oerhaps a touch stronger contrast, this might also be a rather fine image.
Boy, you set this one up nicely! Great theme regardless of everyone's interpretation. The picture tells the story (what a great idea for a song title).
Would a bit brighter image help? Appears a bit muted to me.