It would really do everyone a lot of good to read about visual perception and visual cognition.
I can understand PF becoming fixated on seeing what they wanted to see and not noticing 'the gorilla'. PM's brain is not so fixated and I'd expect more relaxed and neutral. PM is not being coached by PF into seeing the same thing. Therefore I'd expect PM to chirp up quite early on and challenge PF about where they were landing. But that brings the CVR back into the equation, and crew memory after the event.
There has to be some reason that not one, but two experienced crew fell for this imagery.
Indeed. That was also my curiosity, hence my comment above. There should have been 2 independent minds observing this event. I'm still curious whether they were in manual or autopilot flight down to e.g. 1000', and what guidance they were following. The report should discover that.