Last time I entered in Argentina I was using my new passport, and I could see the screen of the immigration lady showing also the previous pictures of me they took in the past. I am almost certain she entered into the system that I was the same person (she linked my old passport to my new passport or something like this). There was sort of a manual "confirmation" on screen required upon comparison of the pics. Basically the lady clicked to confirm that it was me in all of the photos they had.
These were pics taken at the entry points, not the ones in my passport.