This image demonstrates the stereo window concept. The window is the actual position (depth) of your computer screen. At the left, the subject appears behind the window. In the middle, the subject is said to be placed at the stereo window. In this case, the closest part of the subject (here, the right hand of the subject) relative to you is exactly at the level of your computer screen. The right image is with the subject right hand placed in front of the stereo window. The right arm is popping out from the screen. To verify the concept, move your mouse over each image when wearing your red blue glass. As you can see on the figure, the depth of the subject by reference to the computer screen(the stereo window) is determined by the lateral displacement of the one image (the red one) relative to the other (the blue one). When the closest part (here the right hand of the subject) is at the window level, both images are superposed at the level of the right hand.