One is pillar and hinge, the other moves. To open the door one must push the movable sides. Pushing on the hinges has no effect. In this case, the designer had aimed for beauty not utility. No distracting lines, no visible pillars, no visible hinges.
Good design involves making crucial information visible.
Think of a slide projector on which the slides are changed with a single button. Sometimes one wants to move forwards and sometime backwards. To go forwards requires a short button press and to go backward a long button press. This is invisible and makes for very difficult use, even when one knows how to do it. Getting the timing right may be difficult, and this function is not likely to be apparent to all new users.