It's the texture on
Posette I recognized, then-- Andreia was a face morph + body texture set by 3Dream with a somewhat distinctive appearance, which I was looking at recently. Clever you were to pose your model in front of an open door to get that side lighting, which is using the background well.

What to do about the shoulder seams on the dress depends on your artistic goals with the project. In medium distance shots like this, the issue is really barely noticeable, and could easily be solved with a quick swipe of a soften/blur/clone brush in postwork. Even if you make 500 renders with the prop, that might still be more efficient than going back and fixing the model itself/starting over on the model.
On the other hand, if your goal is just to experiment with making conforming clothing and build skills on that task, you're probably better off going back and doing it over until it's fixed, no matter how long that may take (such experimenting is the best way to learn new things).
Do the seams only appear when the shoulders are bent, or is it always there? If it's a sharp elevated ridge that's always present, you might be able to use the grouping tool, separate the ridge polygons, and make them transparent without otherwise making a hole in the shirt. Hard to say if that would work, but if it did it wouldn't take very long. Or alternately, zap them with a magnet if they're distinct enough.
Otherwise (the least helpful answer probably), just about any sort of ready-made female tunic clothing item or even a long-sleeved dress plus a transparency map can be fairly easily made into a similar outfit, if you're just after the item itself. Alternately, there are freebie Trek female dresses available for other figures (not
Posette) on the big R site, you could adapt one of those as a parented prop for
Posette. Or, you could load your character morphs onto one of the old generic Posettes (Amulti, AllMorph, etc) that also have built-in morphing skirts as part of their bodies (if you have any of those), and make the end result that way. Or, if you have endless hours to spend digging around the Wayback Machine, there were several of these particular outfits/characters in
Poser 3 and
Poser 4 days. The P4 one I have unfortunately doesn't have any authorship info or license, so it's against the rules to distribute it here at PF, but these things were out there as freebies in P4 days and are probably archived somewhere.
Really though, unless you're wanting to do close-ups, the seam isn't very noticeable, so just postworking it away after a render is probably what I would do in the same circumstances. Unless you're planning to use it for an animation, which is different (quick postwork for one image is one thing, but impractical for thousands of animation frames). Good luck on the project.