New Camera Features
Apple adds two new features to the portrait mode on the iPhone. These will allow you to take better looking photos from your iPhone.
You can now adjust the portrait lighting on the iPhone to get the effect of moving the lights closer or farther from your subject.
There is also a new high-key mono portrait mode that allows you to create a mono photo with a bright white background.
On iOS 12 you can take a black background portrait photo and you can adjust the depth of field, but not the lighting.