Upload & Sell: On
@beetlefang: Thanks very much for your comment on feedback. I always try to provide constructive feedback when I comment at all. "Why" a comment is made is often just as important as the feedback itself, as it provides context for the requester to evaluate the usefulness of the feedback.
To the original poster, when you ask what the photographer is striving for in portraits (especially for commercial work), the frustrating answer will always be, "it depends." Fashion photography focuses on the clothing (or some article of clothing), and the concept, posing, lighting, etc. all stand in service to the "product" being marketed. Same with beauty; what's being "sold" will determine what's emphasized, whether it's the model herself, or hair/makeup, eyewear, etc. So I guess the first question to ask yourself is literally "what's the point?" in any given assignment. The answer comes from either the client who's commissioning the work or yourself when you have the idea for a shoot. The "point" can be a look, a product, or a story, as long as it's visually interesting and draws the viewer in.
I didn't comment on your original posted photo, but I will here. First off, from my perspective, it's about 90% there. To take it over the top, I'd examine two things. 1. "What's the point?" of her expression? She's a beautiful lady, but there's nothing in that expression that "sells" me on her. It's a blank stare. I'd prefer an emotion of some sort, preferably a smile, or at least a hint of a smile. 2. The lighting ratio. This is purely a matter of taste, but if I were lighting this, I might consider just a tad more fill. This is a very minor point, but if you're "selling" her, I think a more balanced ratio would be preferred. If you're "selling" the outfit, then (aside from the crop) I think the lighting works well.
As for the other posted images, I prefer your second shot of her to the first in terms of posing and crop, but the same comment on her expression applies. Number 3 could be a killer shot if she (again) had a head position and facial expression that draws the viewer to her, something like a "night on the town" kinda look. As it is, it's another blank stare with a head tilt. This could be a good commercial or editorial shot. I like the idea of rendering this in black and white. Of all of these, number four is my favorite. It's well lit (maybe a bit hot), and well conceived, but what takes it to the top is her expression. Chin down, squinty, "who you lookin' at?" kinda feel. There's a story there.
Hope this helps.