Hijab is not much different from many different hair coverings which used to be extremely common throughout the world. All of those had their own religious connections with them. Hair coverings were often a tool of both religion and "modesty", the loaded gendered concept. Nowadays it's most commonly associated with Islam therefore it strikes out as Abnormal. A bra too serves the same purpose, yet its considered the "acceptable" tool of Modesty with no loaded baggage whatsoever while Hijab is the "backwards" tool of modesty with Evil Baggage. The same concept, when it's Muslim racialized, is Backwards and Violent, yet the violence of the bra, because it is accepted among White people too, is acceptable and invisible