After playing with this, I am convinced this is an “OK Google” phone / Google Glass command.
You can replicate this from your phone by saying “OK Google” then “My Inbox” (on Android 4.3 or above) or search it from Google.com with the search text my inbox or voice search by saying my inbox to replicate this for your self.
IMPORTANT: When you click these results, you get a new Gmail interface, displaying the result outside of Gmail and it loads REAL fast. Give it a try for yourself.
No amount of playing with this could produce what I wanted, returning a searchable result from my inbox, by adding keywords to the Google term, my inbox. Being able to search your email / Gmail from Google search via a voice command would be quite valuable in the WEARable market in my opinion.
My question is will we see this begin to develop more over time?