One important component about for the Western world to understand about Islam (and hijab) is the issue of shame. In Christianity, the story is that Eve guiled Adam into eating the forbidden apple, and as a punishment, humanity was exposed to their shame, and began to cover themselves. In Islam, Adam and Eve ate the apple together. Eve is not seen as the original sinner. She was merely one half of a decision that was taken by two people. Hijab is not reflective of shame in this sense. We do not cover because we are shameful of our bodies or our sexuality. We cover out of a sense of awe for our Creator, because of the belief that what He says is right and true and just.
Hijab is not intended as a form of subjugation. Its original purpose was to protect women. Before Islam, women in were considered property. They were kidnapped and raped by powerful men as a way to showcase their power. As the Muslims gained strength in society, they were more and more able to protect the women from this practice. Hijab served as an identity marker. “I’m a Muslim,” it said, “so don’t mess with me.”
I should say that in many strict Muslim countries like Saudi Arabia and Iran, women are forced to wear it, and not given a choice. That expectation is sometimes carried into our mosques here in the US with first generation immigrants. But we should remember that forcing anyone in any way goes against the very nature of Islam as the Qur’an states clearly that there is no compulsion in Islam. That being said, most women who wear hijab choose it for its dignity, its mark of identity, and because they want to serve God.