Don't recognise the software but a possible route...
- Photobooth to shoot and capture to a particular folder (although I suspect it's using an external camera and small monitor for subject to view themselves + did I see a separate remote for shutter release??)
- Could you then set Keynotes to replay as a slideshow all images from the folder (so it would update as soon as new images are uploaded)
There may be some use of Automator to automatically move files???