The orientation lock is an easily overlooked option in iOS/iPadOS Control Center that lets you prevent apps from rotating their view when your device detects it’s turned a corner. This can be useful when viewing a video, reading a book, or engaging in other activities that you don’t want to have the app reformat from portrait to landscape or landscape to portrait. .

FaceTime honors the orientation lock in a way that might confuse other people: they always see your locked orientation.
…
Read more