Selfie walls! Wearables! 3-D printers! The newly renovated basement at Macy's massive flagship store in New York City's Herald Square is full of millennial buzzwords. It's called One Below, and the department store wants it to be a destination for young shoppers. One Below is part of a $400 million renovation at Macy's flagship location and is an interesting experiment. Instead of being segmented by types of merchandise, such as the store's shoe floor or home goods section, the new area mixes all kinds of products for the 13- to 22-year old. It's essentially its own 53,000-square-foot store filled with technology, apparel, accessories, cosmetics, food and a constant electro soundtrack of house music.