Amina Inloes, Amina Inloes is originally from the US and has a PhD in Islamic Studies from the University of Exeter on Shi'a hadith. She is the program leader for the MA Islamic Studies program at the... Answer updated 3 years ago
Within the Sunni hadith collections, there is a narration condemning women who have hair that looks like a camel hump. So, some Sunni Muslims today interpret this to mean that one should not wear a big scrunchie.
Whether or not one acts on that hadith and whether one interprets it to mean this hijab-style, is a personal decision. Apart from that, hijab-style is also a personal decision.