Multiple reasons, just like CBP in the US can pull up your photo to make sure the one on the ID and standing in front of them is actually the person the system

Multiple reasons, just like CBP in the US can pull up your photo to make sure the one on the ID and standing in front of them is actually the person the system says it is. They also compared my old ID photo with the new photo I was submitting when I renewed it recently for the same reason. Though I've never had this particular problem, I believe the police will also do the same thing to verify they're arresting or ticketing the right person. Also keep in mind that Estonia is the size of a (quite) small state in the US, so they're storing things like a driver's license photo just like your state would. You actually don't need a physical driver's license with you in Estonia as long as it's linked to your ID card, so it's really an "all your eggs in one basket" kind of system.