I learned a lot but I do not understand why I would ever use tethered shooting for a model portrait.
Guess you haven't done a lot of this, right? As Mike indicates, it's useful to shoot tethered when there are clients, crew like hair & makeup and even showing images to the talent. Looking at a tiny LCD to make lighting and makeup decisions isn't very useful. We could have set up a still life shot but that wouldn't have gotten a pretty girl to come into the studio...would you rather Mike and I shot fruit and some Mexican pottery? Yeah, I didn't think so :~)