Used to fantasize about these being used to play local multiplayer without having to split the screen

Tilting your head shouldn’t make a difference as ‘modern’ (as in the ones that cinemas started using fifteen years ago) 3D glasses use clockwise and anticlockwise circular polarisation filters, and obviously, turning something 90° doesn’t change whether it’s clockwise or anticlockwise. Other kinds of polarisation filters do care about being rotated, which is probably where the artist got the impression it applied to 3D glasses, but it would be dumb to try and use that kind as obviously, people tilt their heads.

It’s a convoluted way of reinventing an eye patch.

You don’t need to obtain and install a polarized filter when you are only using that filter to block all light going to one eye. Tape a piece of black paper over one lens, ya dummy.