Coach installed an ‘AR mirror’ outside its Soho flagship store as a way to lure customers inside. So far, it’s working. Augmented reality is fast becoming retailers’ new best friend. Over the past few years, dozens of brands from Ikea to Warby Parker to Cartier have started experimenting with variations of AR technology that let customers visualize how a sofa would fit inside their living room, try on a pair of glasses from the comfort of their home, or even see what a $35,000 Cartier ring would look like on their hand.