Fast-fashion retailer Papaya has opened its doors at Westfield Montgomery mall, featuring casual and trendy offerings at moderate prices. This is the latest in the mall’s ever-growing assortment of stores aimed at teen girls, from Aerie/Offline, Aéropostale, American Eagle and Forever 21 to PacSun, Urban Outfitters, Windsor and Zara. These days, data shows that teens and young twenty-somethings are shopping in person more often than their moms and grandmas.