45256848: Camera.app AirPlay mirroring view doesn't rotate to landscape on iPhone X

[openradar-mirror]

Description

Summary:
When mirroring the display of an iPhone X (tested on original 2017 iPhone X) to an AirPlay display and using Camera.app, the mirrored screen is always displayed portrait, even if the iPhone is held in landscape. This only happens on iPhone X, other iPhone or iPad devices rotate the mirrored screen to landscape when the phone is held in landscape.

Steps to Reproduce:

1. Enable display mirroring to an AirPlay display on iPhone X
2. Start Camera.app
3. Rotate the iPhone X from portrait to landscape.

Expected Results:
The mirrored display should rotate together with the iPhone to landscape, filling the AirPlay 16:9 display with the live camera view.

Actual Results:
Only the user interface elements of Camera.app rotate together with the phone to landscape. The mirrored display stays portrait and doesn't rotate to fill the 16:9 AirPlay display.

Version/Build:
iOS 11 (all minor/patch versions)
iOS 12, iOS 12.0.1

Configuration:
iPhone X (2017)

Product Version:
Created: 2019-07-15T12:22:28.036914
Originated: 2018-10-14T00:00:00
Open Radar Link: http://www.openradar.me/45256848