Thanks Lee. That's not my experience. Here's an iPhone 5 photo, shot in (vertical) portrait mode, with the power button and image sensor at the top of the phone. It is rotated by SMC 90 CCW.
IMG_3281.jpg
For landscape photos, I need to put the volume buttons, which control the 'shutter release', on the bottom of the phone to get it to display in SMC correctly. To me, 'shutter release on the bottom of the camera' is 'upside down'.