Arthur Danto says, on Marina Abramovic's "The Artist is Present":

What is clear is that the possibility of sitting with Marina has ignited in the public imagination the idea that one can do more than passively experience works of art, that one can be part of a work of art for as long as one is willing or able.

"Sitting With Marina," NY Times Opinionator, May 23, 2010

More to the point, I think, the performance has ignited the idea that just being with someone, sharing space and attention, is a very powerful and valuable force.

It's one of the most important things I'm learning in this year of my repatriation—that just being with someone is remarkably valuable. It is the doorway to everything that happens beyond the solace of one mind. And inversely, not being with those you care about is the most damning thing you can do to a relationship.

However, to echo Danto's point, I saw the piece on a Saturday; on Sunday, in a different part of town, I overheard a woman of about twenty say to her friend the following:

You just, like, sit there. And she, like, stares into your soul, or something.