The best person on Quora to answer this question is Artem Boytsov, and he has answered it beautifully…you can look up his answers in his profile.

To paraphrase what he has clarified:

There is a difference between being ‘spiritually awakened’ and being ‘enlightened fully.’ Awakening is not uncommon, but it’s still an entirely different paradigm from full enlightenment and ‘awakened people’ are still within the ego dream. Those are the kind of people that may be able to recognize another ‘awakened person,’ because egos still want other egos to reflect back to them, they are not completely alone yet. So they will look for people with which they can participate, in an ego’s dream of ‘awakening.’ It’s doubtful the ‘special glow’ in their eyes is enough, but with some more discussion and interaction, one of these egos can feel like they recognize another one.

A supremely enlightened person can not recognize another enlightened person. There’s no real way to know absolutely, because a supremely enlightened person doesn’t act enlightened, or have any special glow in their eyes, wisdom in their words, or gracefulness in their walk. They appear just as normal, mundane people. As a dude in the marketplace, sharing a bottle of wine with anyone who wants some. But to one who is fully beyond ego and egos ‘recognizing’ each other, to the fully enlightened who are, by definition, completely alone, being able to recognize another is of no concern.

To the unenlightened, everyone is unenlightened. To the enlightened, beyond both duality and non-duality, the whole world is enlightened. Really!