The extended edition expands on 3 endings; The Hospital ending, The apocalypse ending and the escape ending. (So two of the endings you got already; if you haven't gotten the hospital ending yet, you would have to replay the last day to get it - more on how is in the walkthrough-) The drawer is more symbolic of Crow's final choice between defiance and cooperation. If you ask what the literal object in the drawer is, it's the only object Crow brings out during the final confrontation. I hope this cleared things up a little :)