This is from the touchscreen inside a photo booth in Cabot Circus, Bristol.
This is the outside of the photo booth that caught my attention
It’s got a camera and a screen, acting as a mirror. Which makes me think you don’t need the inside of the booth. If the outside had a Kinect-style depth camera it could isolate the person and place them over a digital white background. It could fit in a digital poster form factor. At least, this would work for utilitarian passport photos. So long as you’re ok with everyone watching you pose.
For that use case there’s this marvel from the Post Office that comes complete with an old man watching you.