Are these always-opaque where the "screens" are and only transparent (or not transparent?) elsewhere? If so, I bet it's the intermingling of transparency + overlaid pixels that's hard about the other ones
It sounds like the OP's ones have a button that switches between transparent, semi-transparent mode, and opaque.
I know a pair I've seen in the past was mostly transparent, but then it had an extra piece you could snap on that was just solid black plastic, kind of like a camera lens cover, and it would block out everything but the screens.
