Both.

She wants the right people to look and find her interesting, sexy and attainable, while at the same time doesn't want to be bothered by the wrong people.

Of couse, this isn't true for everyone, but I've found there isn't just one option here.

As a woman I can say when I wear clothing that is slightly more revealing yes, I am going for sexy and yes I do expect people to look. I put it out there, it would be silly of me to be offended by someone looking.

However being a slightly busty girl I can say that most clothing manufactures do not make clothing for women in my age range (early 20's) that fit correctly. They are generally made for these little skinny things with no curves. Even if my aim is not to show cleavage I often end up doing so as it's just a side affect of wearing a D cup.. everything shows cleavage.

In that instance it can be annoying when people don't look me in the eye when talking to me, or shout lude comments at me because my aim was not to be "sexy" but dressed.

So long answer short, depends on the circumstance.

It really depends on how someone looks. There's the 'appreciative' look and the 'lustful-thinking' type of look. Of course women will love the appreciative look. This is one of the reason why we dress up beautifully. To be appreciated, to be admired, to be loved. If you have it, then flaunt it. So if you can flaunt something you have, then you could. It's a great feeling when someone looks at you as if you're the most beautiful person in there.

Then there's the lustful look. Of course women wouldn't want it. Especially to those strangers who she doesn't really like. But of course, dressing up that way will really have some men think of you that way.

She would want people to look ather clevage.

Considering that it is calculated, I would assume that the rest of her attire is a choice as well. Rarely does a woman dress only to make her cleavage look good and not consider any of her other body parts.

Any body part that is highlighted, like cleavage, but it could also be arms or legs, is meant to be noticed and appreciated. Women are taught that their bodies are their primary source of value in this world. So, highlighting their best features may be a way of getting other people (especially men) to value them or to feel better about themselves.

From my own experience, it works. It doesn't have to be cleavage, I get treated noticeably better by men on days that my hair is not in a ponytail or if I have make-up on.

Bottom line, don't gawk at any woman. Once you stare at her cleavage, you've devalued her, whether or not it was your intention. Its possible that she doesn't mind and its possible that its what she wants but if you talk to her and look her in the eye and show a genuine interest in who she is, that will always be preferred.

All women have different reasons for dressing the way they do, so please excuse any generalities. My answer comes from my personal experience as a woman and what I know of my friends' views on the subject.