Tomorrow’s retail stores want to take a page from their online rivals by embracing advanced technology — everything from helpful robots to interactive mirrors to shelves embedded with sensors. The goal: Use these real-world store features to lure shoppers back from the internet, and maybe even nudge them to spend more in the process. Amazon’s new experimental grocery store in Seattle, opening in early 2017, will let shoppers buy goods without needing to stop at a checkout line. Sensors track items as shoppers put them into baskets or return them to the shelf. The shopper’s Amazon account gets automatically charged.