For decades there has been a problem with viewing glass screens of all kinds due to reflections and glare. This was true of early TVs, CRTs, and so on. Since any light reflected off a non-metallic surface is at least partly polarised, one idea adopted early - I mean in the 1950s - was to view with. Polarised spectacles. Another was to,build polarising into the display, sometimes using what is called circular polarising. Many polaroid sunglasses have one lens polarised vertically and the other horizontally. If you look at a screen with a reflection on wearing such glasses and close first one eye and then the other you may find that the reflection disappears with one eye but not with the other. Also, try tilting your head or tilting (left hand up, right hand down, not towards and away). If you have prescription glasses this may not work - it will depend on whether or not the two eyes are polarised in the same orientation. I don't know whether the iPad screen is circularly polarised or linearly polarised.
Even if this does not,help I hope you find it interesting!
Npm