We present custom content on the outer display through CameraCaptureAccessory while a capture session runs (iOS 27.1). Our app is used in the partially folded "laptop" pose: the inner display is portrait with a horizontal fold, controls below the fold, content above it. The person in front of the outer camera sits opposite the device, so for them the outer display's long edge is horizontal.
In Simulator (iPhone Duo, iOS 27.1) the accessory scene is always laid out as 466×678 pt — portrait — regardless of the pose, and regardless of the app's UISupportedInterfaceOrientations. Our landscape content is therefore letterboxed into a narrow band instead of filling the display.
On device, what interface orientation does the accessory scene get in the partially folded pose? Does the system rotate it to match the physical orientation of the outer display, or is it always the outer display's portrait orientation? Is Simulator's behaviour here representative, or is accessory-scene orientation one of the things that only behaves correctly on device? If we have to compensate ourselves, is there a supported way to learn the outer display's physical orientation from inside the accessory scene — reserved regions, the scene's interfaceOrientation, something else? We would rather not hardcode a rotation. Does UIRequiresFullScreen (deprecated in iOS 26) or the app's supported interface orientations constrain the accessory scene in any way?
