I'm going to sound stupid (as well as looking stupid).. but.. so the micro-USB cable is providing powah and ethernets to the Chromecast? So, even the first Chromecasts had this ability built in? Why isn't every usb device offering this? A usb hub with a single ethernet port acting as a router to a raft of RaspberyPis etc.
Paris? Well, she's had some non-standard plugs put in her various ports.