friends and tags

I'm having this concept: that somehow, the existence of our friends would be less complete if we can't tag on our photos in facebook.

I'm thinking, when we know a friend, we want to know the friend's email, add them to our facebook, get te number in our contacts - all of these allowing us to connect with the friend in one way or another. Having one less link seems to mean that the friend exists 'less' in our lives, since we can't tag a friend on facebook, or email a message, or calling the friend. So there is this cycle going on, in our real and digital lives, and they are not opposites, but they reinforce each other in a positive feedback loop. And the significance of these?

Haven't quite figure that one yet.