“Researchers at the e-commerce juggernaut are currently working on several machine-learning systems that could help provide an edge when it comes to spotting, reacting to, and perhaps even shaping the latest fashion trends. The effort points to ways in which Amazon and other companies could try to improve the tracking of trends in other areas of retail—making recommendations based on products popping up in social-media posts, for instance. And it could help the company expand its clothing business or even dominate the area.”