Fantastic. A bit unusual and really effective. No idea what it is, though.
I know this will sound totally bizarre, but it reminds me of one of the scenes in the film version of 'Mary Poppins' - the one where Mary and the children end up on the roof tops with all the chimney sweeps. I'm just wondering what you're doing up here sweeping apparently non-existent chimneys. Curious, but all of us have our eccentricities so I won't enquire too closely.