Climbing features: These shapes can be used as matching handholds for pull-up moves in intermediate to advanced levels. You could also pair them while leaving only a small gap between them, in order to turn them into a medium-size crack. Further bringing them closer one to the other, you will also block a part of the shapes. As such, you will turn them into two highly challenging crimps.
Aesthetics: Their look is extrapolated from the lill-lill boomerangs.