I’m confused when it comes to tznius/erva of a woman. Is the problem that a woman shouldn’t allow her erva to be seen by men or is it that she shouldn’t allow other men to have inappropriate thoughts about her? Or is it something else?
You are asking an important question. There are number of reason why a woman has to dress with tznius, and all the reasons you gave are correct. One of the reasons is because she is causing the men to have inappropriate thoughts, and it isn’t merely “his problem” but it is also the woman’s problem, because she is the cause and source of these inappropriate thoughts. If she dresses properly and not in a provoking way, then it isn’t considered her fault, because she was acting properly and he brought himself to the sin. However if the cause of the thoughts are a result of her dress, then she is an accomplice of the transgression. Aside from this, if her erva is seen by men, they may not make a bracha there, daven or learn torah there.
Aside from this, there are other reason why we should dress with tznius. When describing the clothing that the kohanim have to wear, the Torah tells us that there two reason why we wear clothing. One reason is “lchasos es bsar ervaso”- in order to cover our nakedness. Judaism believes that G-d is everywhere and therefore wherever we are we are in the presence of G-d and therefore we should be dressed appropriately. Obviously this does not mean that we can take a shower or use the bathroom, G-d knows that we are human, He created us and sustains every part of our bodies constantly. However from our perspective we have to act with fear of heaven and not dress inappropriately in the wrong place. The idea here would apply to man and women equally.
The truth is, that there is more to it than only because of G-d presence, and this touches a little bit on the other reason that humans wear clothing. The second reason humans wear clothing is “l’kavod u’l’tiferes” for honor and respect. The way that we dress and present ourselves to others reflects the way that we want other people to look and view us. A judge, lawyer, doctor, policeman, and a carpenter, all dress according to what they want to be associated with, and how they want to be perceived. Could you imagine a judge coming into the court room dressed like a basketball player? What impression and how would that effect the court proceedings? It would be very hard for everyone to respect him, if his own clothing do not command respect. It is the same with everyone. Judaism believes that we humans are a mix of a physical animalistic body that is flesh and bones, mixed with a holy neshoma, which is a part of G-d Himself, a desire to do good, be good and excel upward. (This is why we have a drive to do good while at the same time we have animalistic desires to lust and animalistic pleasures). When a person, especially a woman dresses in a way that accentuates her body, the message that she is portraying is that I am a physical body, look – this is what I am. On the other hand, if she dresses with tznius, she is covering up the animalistic, physical part of her, and portraying a message, “I am not merely a body, I am a human, and someone that has a neshoma and intellect”. I contain many values, goals, ideals, a purpose in life, and my essence is very different than a mere lustful body, and an object of pleasure. This is the message that we give over by the way we dress, and it also causes the people around us to treat us that way. A person that dresses provocatively, and displays to all that she is a body, and accentuates the bodily aspect of herself will be treated that way, and unfortunately we know the negative results that it causes. On the other hand, when a person dresses with tznius, she is portraying self- respect, and inner value, and she will be viewed and treated that way.
I hope that this sheds some light on to this important topic.