Once the attacker has root on your Glass, they have much more power than if they had access to your phone or even your computer: they have control over a camera and a microphone that are attached to your head.
It’s worthing noting that this part of Jay Freeman’s post is more about a potential future exploit than the rooting he achieved, which requires physical access, a Debug Mode that the Glass staff were surprised was in a publicly* available build, knowledge of the adb Android debugger, and also repeated user interaction to execute various parts of the process.
Google aren’t always as open** as they could be, but generally their products are relatively friendly to hackers*** who want to extend and modify the way the things they own work. That said, Freeman is probably right to warn of the issues down the road, and note that a future root exploit would be troubling to say the least.
* where by “publicly” I mean “those who attended Google I/O 2012 or who were lucky in the #ifihadglass giveaway”.
** I know this is a problematic term, but it feels right.
*** to be read in the old MIT sense as “playful manipulators”.
Presented without comment, because I have no words.