Luxury items used to be the ultimate markers of “making it,” especially for Millennials. Older gens grew up thinking aspirational shopping meant saving up for (or dreaming about) high-end pieces that signal status and taste. But teens now are flipping that entire idea on its head. Instead, they’re all about viral products as the “it” items to have and be seen with. Owning the latest Stanley cup, Trader Joe’s tote, or even a squishy can feel just as cool—if not cooler—especially for a generation that has romanticized affordability and dupes. And anyone on social media can decide what’s a must-have...