In outer space, a starlight is coming from the right. This ray enters the pinhole of a pinhole camera and is reflected upward by a mirror set at 45 degrees upwards in the camera.

As I wrote before, when the camera moves to the right or left (at a uniform speed), the position where reflected light hits the inner wall of upper part of the camera will move (angle of lincident light and rleflected light relative to the mirror is generally different). Incident light is propagated in aether, and reflected light follows the emission theory.
http://www.asyura2.com/0306/idletalk2/msg/1242.html#c207