Vorbau: (n), buttress, projection, front end, front building, etc, etc, etc. Or, could also be interpreted as “balcony.” And therefore we have…
While perhaps shoes or dry-cleaning services were a more obvious answer, the closest guess goes to JoSch, who thought it might have something to do with construction machines.
this lady these ladies are advertising for a company specializing in balcony renovation, and building facade repair. While the jokes may be a bit obvious… it clearly gets attention so well played!