Walker Percy addressed a similar phenomenon in his 1954 essay, “The Loss of the Creature.” He discussed how our anticipatory framing of an experience, especially a visit to a famous place, keeps us from relating to what we are seeing in an unmediated way.
What my student described is an exaggerated example of this sort of detached relationship to living. The experience is superseded by its representation on a Facebook page. The self is edited and framed in the manner that one might curate a museum exhibition.
There are actually two issues here: detachment, or the failure to experience life because you're too concerned about how you will have experienced it, and positioning, which is intentionally albeit perhaps semi-consciously representing (or misrepresenting) yourself to others. Neither is a new phenomenon, and both are more complicated than they initially appear.
Detachment, for example, is generally a bad thing, the opposite of engaging. In her forthcoming memoir, for example, the author Terry Tempest Williams describes how her mother bequeathed her her journals--years and years worth of blank books. Williams is understandably perplexed by that: on the one hand, it can be interpreted as the mother's gentle rebuke of the daughter's lifelong tendency to analyze what happened rather than experiencing it. (She also suggests that it can be interpreted as a critique of religion--her mother was Mormon, and Mormons are encouraged to keep a daily journal (?)--or perhaps as a bit of posthumous mischief). On the other hand, some capacity for critical reflection never hurt anyone, and particularly during moments of distress it is common advice to try to observe the events and feelings happening to you as though you were floating six inches above your own head.
As for the positioning--I suppose we all do it occasionally (job interviews, dates), but as with any other form of fibbing, the effort required to maintain a convincing facade over the long haul is so considerable that few people are genuinely capable of it. The better strategy would be to take cues from your own positioning about what kind of person you're trying to be, and then become that person, so those traits are just naturally manifested. And if you're going to be criticised you might as well be criticised for the flaws you actually have, in which case some measure of fairness is preserved.
The underappreciated upside to the fact that so much of this self-curation is now being done online is that it's become easier to see how other people position themselves, which is typically revealing, and often touching.
Relatedly: "The Art of the Impersonator," Sanford Schwartz on Cindy Sherman.