Pretty sure this is what the EU is also introducing, instead of passport stamps and border agents.
It's 1 person sitting in a booth verifying 8+ automatic passport and "person scanner" (ie, takes a photo and fingerprints of you). Matches entries and exits to the Schengen zone. They approve you, and you pass through the gate.
Not sure about the "retention" aspect, tho. Certainly retained for the 90 days in a 180 day period thing. Beyond that? I dunno.
But any border control zone is going to have CCTV which will have its own image retention policy.