Comment by Terr_

[Self-reply with side-topic] Assuming a rectangular display rotating in standard air... what glass enclosure would be best?

My intuition says "change the sphere to a cylinder", because then we can minimize how much air could be passing around the sides and top of the display-rectangle, potentially curling around and causing turbulence and noise.

However, that introduces a new issue of visibility: Big flat surfaces have different glare/reflection problems than a spheroid does. It may become harder for the user to see clearly, whether from external glare or from internal reflections in a dark room. What if the top face of the glass cylinder was very slightly curved outwards, to avoid the worst-case scenario where you just can't look down into the device from certain angles? Depending on the refractive index of the glass, it could just be a thicker top, so that it doesn't create dead-space on the inside.