Noel- I take it these sidewalls are not seen on another hole @Deal?(or anywhere)
It does remind me of, in concept, to some of the greenside moundings at Pinon Hills. The difference with those PH mounds is they are circular in nature, so they turn, or run-out of bankable real estate. Making the exact spot to bank the shot, much smaller. While sending the less accurate shot, in a completely different, ususally undesirable, direction. Also, they are not maintained to a grass height, where putting onto them would be an option. What a pity!
Come to think of it, Lou Duran's Famous 14th hole bunker shot at Black Mesa, utilized similar sidewalls and creativity.