I'm reading The Case Against Reality and there was example about necker cube and that how it's impossible to see the both versions of it simultaneously. First time I saw it mentioned in Peter Watts' Blindsight where it was pointed out that humans can't see both cubes simultaneously but vampires in the book can. It was fiction so I dismissed it but now I'm reading this book and saw this example I think I can see both versions of the cube simultaneously? I can flick both version on and off which I think is normal but I can also see them both I think. They kinda just blend together. Am I just perceiving it wrong or something?