"It is the glory of God to conceal a matter, the honor of kings to search it out."
Proverbs 25:2

Some say women should dress modestly out of respect for men, who are led into sin easily by the lack of clothes covering a woman's body because their brains are wired to be visually stimulated.   While it is noble to consider how one's behavior affects others, it is NOT the reason for modesty.   Women are called to modesty because of the great mystery revealed by their bodies.  The modest woman recognizes that her sexuality is a precious and beautiful gift.  She realizes that she is a mystery intended for only one other, and that this person for whom her  gift is intended must aspire to be worthy of such a great gift. 

The modest woman veils the intimate parts of her body with clothes, only to unveil the sacred mystery of her body for the man who has proven his worth and earned the right to lift her bridal veil on the wedding day.

The modest woman veils the intimate parts of her person - emotionally and spiritually, as well.  Recognizing that a man must aspire to be worthy of her heart.  She recognizes that the body is sacred because it reveals the entire femininity of her person - the femininity of her thoughts, of her soul, of her actions - and so she does not reveal her entire identity to a man as soon as he pursues her, but it takes the honor of a king to search it out and prove that he is worthy to know her mystery.

The following video provides a good explanation of modesty, regarding both the body and the interior person.

"A woman's heart should be so lost in God that a man must seek Him in order to find her."
--author unknown