I was talking to a coworker who says he has SEVERE reactions to secondhand cigarette smoke [eye ulcers, coughing fits, etc]. I showed him my
device, explained the concept, and with his consent we tried an experiment. I sat next to him in the meeting we were attending, and I happily vaped my brains out. He reported that the WAS a light odor [which he could only describe as "sweetish"], but he did not find it objectionable, and did not have any reactions to it. None of the other folks at the meeting could smell it, but it was a little distracting as people kept staring at the clouds of vapor
My wife has never reported being able to smell the vapor, and she complained ALL THE TIME about the analogs, even when I smoked outside
I think the flavors are mostly so subtle that we as the user can taste them somewhat, but only the really strong ones [like banana or strawberry] might get picked up by a nearby person. At any rate, I don't believe it carries very far...