[When Isaac gets angry, he doesn't know how to use his words. Anyone on the sixth floor would have very likely heard the door to his cabin slam with way more force than what was necessary. Yes indeed, it's time for lost-my-warden rage 2.0. Emo: he has it.
Not too long after that incredibly loud slam, the camera flips on to show a wide-angle shot of the far wall of Isaac's cabin and a stack of canvases propped up against it. A couple of seconds later, Isaac himself walks into frame carrying an open can of black paint, stolen borrowed from the art room. The only painting fully visible to the camera is
Ted's painting of the Joker, which he steps back to eye scrutinizingly for a moment before he completely and utterly destroys it by pouring the entire can onto it.
Letting the empty can clatter noisily to the floor, he strides back across the room and crouches down in front of the camera, his expression blank. The paintings left at his door from the recent temporary power-swap with his warden were his notification that Ted isn't on the barge anymore, but he's going to say the few words he wants to say, goddammit.]
Neither of us got what we wanted. It was pointless--all of it. Why should I even try anymore?