I'm mostly interested in the manufacturing technology -- seems like they're doing some kind of friction/ultrasonic/diffusion welding between the titanium frame and the aluminium insides.
Apple is fairly silent on these kinds of things, but it really is impressive how much they invest in leading edge manufacturing - huge CNC factories, this insane mixed metal weld, laser precision drilling…
That's a notoriously difficult weld to make: https://doi.org/10.1177/14644207211010839
I would love to know what process they're using and how they've got it reliable!