GSM Arena has a good report on this:
The big breakthrough here is hidden beneath the curved 6.67-inch AMOLED display where we find a 20MP selfie camera (1.6 µm sized pixels when the 4-in-1-pixel binning is applied) leaving the screen unblemished by cutouts. The workaround required a whole new type of flexible display and redesigned circuit array to maximize the transparency and in turn light reaching the selfie cam sensor.
Xiaomi used a new micro-diamond pixel pattern paired with rethought algorithms which ensure minimum light refraction. The area above the camera packs 400ppi density so even the tiniest of text remains perfectly readable. The whole panel is protected by Gorilla Glass Victus, features a 120Hz refresh rate and FHD+ resolution.
The rear camera setup is equally impressive with a 1/1.33-inch 108MP ISOCELL HMX main sensor with OIS. It’s joined by an optically stabilized 8MP periscope module with 5x optical zoom and 120mm equivalent focal length. A 13MP ultrawide snapper with a free-form lens and a reported 1% edge distortion completes the trio.
Other key specifications include:
- stereo speakers tuned by Harman/Kardon
- Snapdragon 888+ chipset
- 8/12GB RAM
- 4500 mAh battery
- 120W wired charging
- 50W wireless charging
Mix 4 features a ceramic back and comes in white, black and gray colors. If this comes to the UK (via a global edition), we'd be talking £900 approx., I estimate. Pretty impressive all round.