There is a video in youtube about a guy controlling a BB8 toy robot using one of this "mind readers"
it explains how this works, in short :
The device is programmed to read specific brain impulses, ie: moving your hand in a certain way
when the impulse is recognized it then triggers an action
so ... no it wouldn't be taking pictures of everything that attracts your attention just by default, unless it is programmed to recognize *that* particular impulse
in the bb8 video the control is done via wireless - bluetooth I think - a bit less intrusive than the google glasses, still requires the "tiara" over your forehead
edit: here is the video , nothing to do with photography, it's more about using the mind reading device and how it triggers actions
https://www.youtube.com/watch?v=K-4mp_e5v4A