Not sure how to really explain this so just check it out.
I took a quick selfie and opened it in the Snapseed app.
To start editing, click the pencil in the lower right.
1. Scroll down to the very bottom.
2. Click the Pose button.
Click on the center icon and drag up/down/left/right.
It actually moves your face while the rest of the image remains in place.
Not a big selfie taker but this seems to be a interesting idea.