Is "rear view mirror" a joke, or maybe just a lower res cheaper camera pointing backwards, or maybe this leak isn't legit?
Either way, looking forward to seeing the headset!
This is english translation of original Chinese leak [1].
Lot of formal/informal colloquial terms gets lost in translation. Yes you could be right - wearer of the headset would be aware of environment behind their head and for that this could be the camera system.
My favourite (possibly apocryphal) example of meanings lost in literal translation, is "water sheep".
(Hydraulic ram).
Through an unrelated anecdote, in my head this is now bound to the music of "smoke on the water", with a sheep impression for the guitar (bass?) — "Sheep on the water, ba baa baaah, ba ba ba baaah"
