Step away from the spraycan

A group of people (or a very industrious individual) is engaging in a unique - as far as I'm aware - form of street-art using plastic cups:


I first spotted this last year in Arnold Place, just behind Oxford Street. Every now and then someone goes to the effort of taking bits of it down but it's always restored before too long.
I just noticed a new one on Flinders Street, Surry Hills the other day:



I don't know who's responsible, but I do like.