: I'd like to preface this by saying since the last time this came up I've seen
: the H2A and H5 cutscenes, and they are going for a dressed look-- now. I
: reject the idea that that overwrites or invalidates how she looked before,
: especially since she didn't look dressed in Halo 4 or H1A.

She wasn't 100% nude either. See my last little section below.

: Her butt is probably also evidence, but with that you could say it's just
: kind of wedged up in there. How form-fitting a bodysuit is was a sticking
: point previously, and it's painfully obvious to me from some depictions
: that there's no covering.

Quirel got that covered :P

: I keep hearing there were nipples in Halo 3; I can't seem to remember a time
: I saw them clearly, so I won't say it's definitely true.

Clothing can still show nipple bumps. That doesn't mean the female is nude. But the effect may be the same - anyone with a slight sexual thought may get those feelings by merely seeing the impression of nipple bumps; in Cortana's case, as Frankie said, that's the sort of effect she was going for in how she chose her appearance. Demand attention. Shock value.

: I think they never had that firstly because Microsoft
: would flip out and ratings boards would classify it was adult or refuse
: classification (which means not allowing it to be sold), and secondly
: because until the last game or two it wasn't really possible to have it be
: as subtle as it would be in a real female form (especially with how small
: Cortana usually is).

I talked about that in an earlier post. Whether it was artistic limitation or explicit character design. As it's confirmed that she's giving the impression of, then it was explicit character design. But that sitll leaves the door open - if ratings were less strict, would they have been more detailed? Who knows. We have our answer for her right now, and that's that she's not, by definition, nude.

: That's the point. I don't think you are talking about the objective
: appearance, I think it's your subjective interpretation of the appearance.
: I think the way you view it is clouding your view of what it objectively
: is and was, and what it was intended to be.

I really don't know how this can be any more objective. She isn't nude, from a human standpoint. She just is not. That's not subjective, and can't be any less subjective than it already is. A human female nude has details that Cortana has chosen not to display.
She's not nude: She's an AI hologram who has chosen an appearance which gives the impression of nudity (and that's from the horse's mouth). She's never been nude. She's always been a hologram with a very idealized, near-nude form projection, sometimes limited by console technology, and visually altering to a degree as her story progressed.
You can imagine that she's nude, but that doesn't make her nude. (and don't turn that around as if I can imagine that she's not nude but that doesn't make her so - rly, she just isn't)

Heck I'll even say this - she's not nude, and she's also not not nude. She's just a projection of a female form, who to humans, may appear nude. How many other ways can it be said? :P There are implications of patterns and design consistent with typical human garb. That doesn't mean she's clothed (she's just light; everything is an impression). Just like crevices don't mean she is nude.
She's a hologram with a chosen appearance for a purpose. That's all there is to it.