You can control screen rotation on device.
By default, InstaVR generated app's screen orientation is fixed to "Landscape Left".
However, some google cardboard headsets are designed to attach with "Landscape Right".
At that situation, this option help you to use "Landscape Right" instead of.
You can also select "Auto" option. With "Auto" option, device can automatically select "Landscape Left" or "Landscape Right" automatically.
However with "Auto" option, viewer will have “flip screen” when look up because gyro recognize the device is rotated.