When I first saw it I thought it might have been an advertisement for a business in that block. Maybe it was for an accountant who was exhorting people to lodge their tax returns?
But there was no number of website address nearby on the wall, so I realized it was street art.
Recently I did some Googling and discovered that it was by an artist named Elliott "Numskull" Routledge and was commissioned by the Inner West Council in 2016.