One side only is funny. It looks like a recovery or stabilizing point with the hole in it ...handy if you are on an extreme angle.
The tab hangs down right ? If so possibly acts to protect a vulnerable part by lifting the vehicle at that point if say crossing a log ie when fitted if you run your eye level down the two sliders is there a something near that tab point where a little more lift helps clear a component ? If not I got no idea why only one.
