I can see two likely explanations for this magnificent display:
1) The outlet pipe from the meth lab next door isn't elevated enough
2) The house is occupied by Resbians*
It's touchingly Reservoir that following such a flagrant outburst of freeform expression the household has continued to manicure the lawn with Diophantic precision, and then parked a car on it.
* Resbian: A lesbian from Reservoir.
Apparently this is a burgeoning demographic at present in the 'Voir. Exciting times. If you thought the collective noun "A Northcote of Lesbians" was edgy, try queue jumping a Resbian at the Broadway Puff 'n Stuff.
With thanks to A for the pic