Oomis said: You were saying that BY girls should not have explained to them the workings of a man’s mind because it is not the ikkar. I believe it IS ikkar and there SHOULD be plain speaking to girls upon whom you want to impress those concepts.
Technically it is probably not the Ikkar. The ikkar is to be tzanua in front of Hashem, v’hatzneah leches im elokecha. BUT, the reality is that it is not so easy to feel Hashem’s presence in our every day lives, etc and therefore we need reasons for mitzvos.
The fact that the way a woman dresses will cause certain reactions in men should be taught to the girls so that they understand what they are doing so that when pure yiras shamayim isn’t enough to deter them from dressing a certain way, perhaps the physical reactions that they are causing will.
I addition, even women who are dressed appropriately still shouldn’t be hanging around where there are men, for instance they shouldn’t be hanging out in front of the shul as the men are leaving no matter how appropriately they are dressed because even when dressed tzanua they can cause hirhurim. This knowledge is probably the best way to get them to change their ways, because they don’t realize at all what they are doing, they don’t think they are doing anything wrong, there is no clear cut halacha that says not to hang out in front of the shul, they have to apply seichel to figure it out and for this they need to know what it is that they are causing – even the married woman who have some idea of what goes on in a man’s mind does not understand completely or they tend to forget, to push it to the back of their mind.