The mask serves several functions. First, it covers every trace of the Arkham Knight’s identity. Second, it gives him a heads-up display, so that he can track down the actions of his private army, as they take over Gotham. This information is actually streamed inside his visor, and Rocksteady emphasizes that this gives the illusion that his eyes turn an inhuman red. Rocksteady words this description in such a way that they make it clear that he is a man, and that he is not a robot or android of any sort.