 CONT: We see Peter walking down a hall, with the ceiling exit sign  reading backwards, and Peter looks right, then cut to inside the  room, then he continues walking down the hall, walking past a fire  extinguisher. Later on we see the same shot mirrored so that Peter  looks left and into a different room. You can tell because the fire  extinguisher is now on the other side of the wall and the ceiling  exit sign isnt backwards anymore.