The rolling bench is a surprisingly simple and very efficient conceptual design. The rolling bench does essentially that—rolls. Let's say it just finished raining. Nobody wants to sit on a wet bench, so on the side a crank allows the wet side to be rolled around to expose a presumably clean and dry side that will welcome your rear end for sitting.
It was designed by a Korean design firm, and one aspect of this bench that was probably not taken into consideration is the ease of clearing the bench off. Hobo sleeping on your favorite bench? Just crank it and let the hobo roll off into the grass. It could make replacing the bench easier as well—just replace the rolling part when it gets too dirty.