ROFL!!!
Awright, who in the club is responsible for doling out and rescinding people's membership cards?
Those are nothing more nothing less than 3 regular household floor polishers like mentioned above (3 regular 3-brush polishers, adding up to 9 brushes).
Electrolux and other famous brands used to sell them decades ago, that seems to be a picture from the 40's poking fun at something. Polishers like that were very balanced and easy to maneuver, to the point that one of my neighbors had one with a broken handlebar and she used to polish her floors using only one hand. They also had motors in the 350-400W or so, so it's easy to connect 3 like that to one outlet.
In fact, I have no doubt that the 3 machines connected like that would be even *easier* to steer, because then the small bias to run to one side or another would be compensated by the arrangement.
Domestic 1-brush polishers were also very easy to use, they did not use the same procedure of tipping the handle one way or another to steer, you just moved them left or right or back or forth just fine.
Cheers,
-- Paulo.