The photo above is the only one I can find that actually shows the sliding door of a two person confessional. By that I mean, the priest is in the center and two penitents enter (and at the same time as the other) the two sides and kneel and wait their turn for confession.
But, you ask, since you are too young to remember this norm for confessionals, how do you keep from hearing the other person's confession?????
That's a good question from a malformed young Catholic, not that it is your fault.
There were sliding doors on the screen on the priest's side. He would slide the door open on one side to hear that person's confession and then close it when finished and open the other side. Thus the penitent would not hear the other person's confession, although he might hear mumbling or the priest's mumbled responses.
It was very important for you to listen to the other side's sliding door being closed by the priest and then your side being slid open by the priest to let you know it was time to Confess.
When I was a child, sometimes I couldn't distinguish which side was opening and closing, so at times I started my confession to a closed sliding door! Oh, well.
Now, the more modern version of the Confessional above, which I can't find a photo, would not be a piece of furniture as shown, but built into the wall of the church and normally toward the entrance of the church, but in the nave, not the vestibule or narthex. There would be doors or heavy curtains to keep others in line from hearing the penitent confess his sins.
The original church of my childhood parish in Augusta, St. Joseph the Worker, was a 1950's A-frame building. There were two confessionals opposite each other. Originally, they had very heavy burgundy drapes instead of doors, which I hated as I was paranoid those outside, like my parents and siblings waiting to go, could hear me.
In answer to my prayers, doors were eventually added. I loved those doors.
In addition to the sliding doors, there was a white cloth placed over the screen which looked like a corporal cloth. This helped in maintaining anonymity and also from spreading germs either from the priest to you or you to the priest. It was like the coronavirus masks we are all wearing now.
Thus, in this set up, the traditional confessional with a separate enclosed space for priest and penitents and the cloth over the screen with sliding doors that open and close, germs in an epidemic and a pandemic could be nipped in the bud.
Reason 999,134,194,701,043,143,0171,734,017,153 to recover pre-Vatican II sensibilities in the Confessional and the Holy Sacrifice of the Mass.