Jeff Bezos first sketched out the device that would become the Amazon Echo on a conference room whiteboard in early 2011. He wanted it to cost $20 and be controlled entirely by voice. Its brains would live in the cloud, exploiting the company’s Web Services offerings and allowing Amazon to constantly improve it without requiring owners to upgrade their hardware.The first-ever depiction of a device with Alexa—the artificially intelligent virtual assistant that Bezos would name after the ancient l...