It was probably invisible but there are actually 2 parts to that kiosk visit. The first was to set up your EES file, which needs key data from your passport plus your biometrics. Under current regulations, that EES file is going to be valid for 3 years as a one-off process (and my hunch is that it will eventually turn into a rolling 3 years, it will only expire if you do not enter Schengen for three years). The second part, having created your EES file, are the questions connected with that visit - the subsistence and bona fides questions. The third stage, away from the kiosk, is the border officer checking and clearing your data, that's one-off too.

The next time you go through, if the e-gates are enabled for this, then you can use the e-gates without registering your biometrics or your EES file. If the e-gates are not available you go via a border officer. Now in theory (and in practice in Sweden) the border officers could ask you the same "have you got enough money?" and "purpose of stay" questions, but for most nationalities in most airports this just doesn't happen. Ditto the e-gates.

The hesitation I give on this is that during the first 6 (or reportedly 9) months it is a mixed method system so I'm sure some people will get registered more than once, or at least sent to the kiosks. More information on the EU's website for EES.