After having finally played this game, I call bullshit on this trailer.
According to this trailer, Corvo is visited by the Outsider in the prison dungeon where he then receives his mark which will let him "blink" out of the prison etc.
But in the actual game, that's not at all what happens. Corvo doesn't get his powers nor meet the Outsider until much later, after having already escaped from prison.
If game trailers could stop having stuff happen that doesn't actually happen in the game, that'd be great.