I think reading the article may clarify her reasons. I have not, so I could only speculate.
I hate to ruin any fantasies, but many hijabis are just wearing normal, everyday clothes underneath, in fact, some women just cover their hair and wear jeans and a tunic top. Some wear as little as possible under a long overdress, cause we live in very hot climates. I don't cover my hair in the states, but I wear modest clothes.Muslim Pakistani women often wear traditional Salwar Kameez with the long scarf draped modestly over their chest, but hair is not covered-even in Pakistan. Some cover their hair for tradition, while wearing tight jeans. Sometimes they are wearing their pajamas under the robe. I did that in Mecca. Striped cotton pajama pants and a tank top. It was 105 degrees. I didn't want to pass out in the heat.