Step 2: A word on door types
To have something outside the doors will mean this mount will need to be thin enough not to be detected.
Also, the rubberized strip on one door side has a bend to it which corresponds to a bend on the opposite door. The bend maximizes the contact area of the rubberized surface and stops people from sticking things through the doors once closed. This is another safety feature deterring the urge to stick things through the doors while closing.
Since this assembly is outside, the mount design needs to be slender enough to fit through, but strong enough to support the weight of the camera and the forces acting upon it.