Photo: Retailer It was a day off for public-school kids when I found myself sitting in a corner of Joe & The Juice in Soho. At the tables nearby, gaggles of tweens and teens filmed TikToks, unboxed hauls, and decided where to go next (Blank Street, most likely). One thing caught my eye: a zip-up cable-knit hoodie from Brandy Melville that no fewer than six girls were wearing. I wondered: Is this the new “It” sweater, taking over for the $38 dupe of Polo Ralph Lauren’s American-flag sweater that