In my view, a "feminist act" refers to an act that either constitutes a symbolic challenge to patriarchy (which implies active rejection of the patriarchal system rather than merely coping with it) or actively contributes to undermine patriarchy's material or ideological foundations.
I do have a lot of sympathy for the notion that the general principle of using sartorial choices to offend male sensibilities or male entitlement and to deflect or confuse the male gaze can, in fact, constitute just such a symbolic challenge. I'm just not sure that this is in fact a case of that for most people. (I know anecdotally that for at least a few women it is but the plural of anecdote is not et cetera.)
That's an idea I personally have a hard time to swallow, considering my understanding of how patriarchy works. In my understanding, the objectification of women goes hand in hand with the obsession with "modesty", they are two sides of the same coin. On the one hand, there's the idea that women are sexual commodity for men to use, and on the opposite side, the idea that women should stay chaste and preserve themselves from men. I think that is roughly what is meant with the "madonna/whore complex". The genius of patriarchy, so to speak, is that it invented both a thesis and an antithesis, that it has framed the debate in such a way that i can draw strength from both sides of it. Adhering to one side of it to counter the other one strikes me as a futile attempt, at least at the symbolic and ideological level (again, I'm not claiming that it cannot work in certain practical situations).
I think you've nailed it, with respect to how I would approach it. It is not possible to determine in what way women would present themselves if there were no 'critics'; either men who were critiquing on the basis of sex; whether wanting a 'loose woman' or a dutiful wife both of which are extensions of patriarchal thinking, or peer criticism from other women who demand that of women themselves.
This is merely from my own experience, but as a non-heterosexual male, when in the company of women, I don't find that they cover up to an extreme in private. If I was being honest, from women I know they tend to dress for comfort and probably 'wear less' than in public, but while it's less garments it's for comfort and not for a sexual end. I would say as a male that the same is true for us. Which I think is probably close to a 'neutral' non-sexual state of dress.
Therefore I would contend that of the two extremes and they are both extremes driven by the same means, completely covering the body in public is the most distant from what we could consider a neutral state of dress/undress. I have argued a similar point with respect to sex and food; a hedonist is 'obese' towards sex in the same way that someone who is abstinent and seeks abstinence in others is 'anorexic' towards sex. Eating too much is closer to 'eating' than starving yourself is and having constant sex is closer to 'having sex' than completely shutting yourself off from it is. It might be a contentious observation but as someone who eats and who has sex in moderation as most people do, I somewhat disturbingly but almost entirely by default have more in 'common' with a glutton of both.
