Q for both pills: what obligation to women have to dress modestly, and what obligation to men have to not sexualize how women dress?

I've arguing (not heated, discussing really) with my girlfriend about where this line should be drawn.

A more specific instance of the question would be: in a workplace environment with a casual dress code, do women have an obligation to avoid baring their shoulders, exposing bra straps etc., and showing cleavage? If so, where do you draw the line? Should they be fully covered? Why should we treat that minimal skin exposure in such a sexual way? Likewise, if you think women don't have this obligation, how far does the argument extend? Should they be able to come into work in their underwear, or in a less extreme example, otherwise scantily clad?

Personally I think for casual dress, even in a workplace environment, moderate cleavage/skin shouldn't be sexualized. It's harming nobody and it isn't asking for attention. I think people should be able to dress however they want as long as they aren't explicitly and intentionally distracting you with actions that they take while wearing that dress. It's not necessary per se, and I don't think wearing something like this inherently draws attention to sexual body parts. Cleavage is just part of a woman's figure and if she chooses to show it, that's her prerogative. It's anyone else's choice to sexualize it to the point where it affects them.

Here's an example of a garment I think is somewhere on the line between acceptable and not acceptable. I think this is okay if the workplace setting is casual, but a more formal one, probably not. And I'd hold the same standard to men, of course.

http://outfitideashq.com/wp-content/uploads/2014/12/semi-formal-outfit-ideas-women-7.jpg

This relates to the red pill because it involves their decisionmaking process in terms of what women to approach and how they interpret the dress of women when analyzing their intentions etc. Do trpers think this is an invitation or a sign a woman is available? How do trpers think dress should be used to read a women's intentions, given their interest in evaluating a woman based on her actions and not what she says, something I've heard touted by trp many times?