"The relative symmetry of a key's shape makes its orientation difficult to discern at first glance," writes Nendo, explaining the design of their L-Door Key. "When the bow becomes L-shaped, however, the principle of leverage enables the user to turn the key effortlessly, like a hex key."
"Further, the asymmetrical shape allows for easy identification of the key's top and bottom, front and back, so users with low vision can feel the key's correct orientation in their pockets or in unlit areas with only their fingertips."
It's an interesting concept, and Nendo says that "The design does not add elements to standard keys but instead structurally shifts the bow off center for operation, so the key is neither wider nor bulkier than usual." Even still, I do wonder how this would sit in one's pocket.