[lostsock]

> 37% greater pixels-per-inch. And 1.3x larger color gamut

Is referring to the display resolution inside the headset

> Full-color mixed reality, with resolution 4X higher compared to Quest 2

Is referring to the camera resolution on the outside of the headset

> slimmed down the optical stack by over 40% compared to Quest 2

The are using a new technology, pancake lens, giving effectively the same (or better?) performance but taking less space to do so.

> Real-time expression tracking

You can turn it on or off as a user. I don't know if they've optimised it to only "run" when the software you're interacting with is setup to use it or not.