It's palm-sized with a single blue LED light indicating a connection, but honestly you don't ever need to look at it: it doesn't need line-of-sight to your handset because it uses a wireless protocol called WiFi Display, which means you can happily leave it dangling out of the way behind your TV.
The new version of WAP, or wireless application protocol - a standard that allows mobile devices to display Web-like information - is due out by January, and is expected to create a PC-type environment that could open the door to attacks.
Canonical originally planned to replace the aging X with another display server called Wayland, but the developers apparently couldn't bend the compositing-friendly protocol to their cross-device whims.