Beyond that, this chameleonic glass does seem to have some practical benefits too, like the ability to act like a neutral-density filter for the camera. Long story short, it can reduce the amount of light entering the cameras by about three stops (the photographic equivalent of "a lot"), so you can shoot wide aperture shots with plenty of bokeh in Pro mode without worrying about overexposure. They're also really helpful for shooting video in bright situations, too, or so my producer told me while shooting our hands-on video.
So, yes, maybe OnePlus is right to try and push this particular envelope. Or maybe it's too expensive to produce at scale, or not durable enough to hold up to everyday living. We won't know for sure until OnePlus does a lot more testing. Still, the whole point of a concept phone is to get people thinking about what's possible instead of what's simply practical, and after chewing on the company's work for a while, I'm starting to hope they don't give up on this idea.