CompositeImage is always 2 for images acquired using AVCapturePhotoOutput

I use AVCapturePhotoOutput to take still pictures. I print metadata with the following code.

func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    guard let data = photo.fileDataRepresentation() else { return }
    let ciImage = CIImage(data: data)
    print(ciImage?.properties)

The following CompositeImage can be obtained

CompositeImage = 2

However, CompositeImage will always be 2 even if HDR is turned off as shown below.

device.automaticallyAdjustsVideoHDREnabled = false
device.isVideoHDREnabled = false

The expected value is 1. Could you find the cause of this?