I never knew those existed! I had to look it up. We've had the technology for a while, so it makes sense, but I'm surprised at how widely available it is.
I also saw mention of some theaters projecting captions on their back wall as a solution, then providing cup holder mirrors for whoever requested the accomodation.
I second the curiosity. What would it look like? Sudden crouching? Paralyzing indecision?