As soon as you get control of Sherry, turn around and pick up the doll. Examine it and get the cube. Put it in the puzzle box, then pick up the first cube and move it 2 spaces to the right. All of the cubes are in the correct spots now, you just have to rotate them (I start from the far left side) so the symbols match. Take the scissors and cut open the paper on the wall, hold L2 to crouch and go through the hole into the next room.