Philip Hensher: Do you want an experience or just to film it?

The comedian Sarah Millican has an on-stage persona which is warm, suggesting the sharing of confidences; her audience responds to her like a cosy best friend with a nice line of rude remarks about sex. Some people seem like stars on stage to their audience; others give the impression that they could be your best friend, if there were only time. Sarah Millican is very much a best-friend sort of performer.

So when Millican spotted an audience member, Clare Evans, filming her show in Wolverhampton and mildly humiliated her from the stage, Mrs Evans took the comments in good part. Afterwards, she posted on Millican's Facebook page a comment about how much she'd enjoyed the show, saying: "I was the lady videoing you in the front row."

In what followed, it is interesting to see how social networking sites, as well as Millican's persona, had created a bizarre delusion in Mrs Evans's mind that she actually was, in some sense, a friend of the performer who would be forgiven for taking a minor liberty. But she was not a friend. The liberty was not, in Sarah Millican's eyes, a minor one.

The comedian wrote back, quite sternly, "Did you delete it as I take these things very seriously? I really hope you don't come to any more of my shows. You're not welcome if you're to behave in such a disrespectful way. What you did is basically theft and against the rules of the theatre."

In the usual manner, people weighed in on both sides. One side believed that people who had paid for a ticket for a performance should have the right also to record it. Others, correctly in the eyes of the law, believe that the performer owns the rights to live performance.

Manners at live performances have changed enormously in recent years. Take a look at an enormous rock concert from 20-plus years ago – say the 1985 Live Aid concert – and one of the very striking things is that whenever you see the crowd, there is nobody holding up a camera. The experience was live, and the audience went to surrender to the moment.

Now, all sorts of events are experienced by their audiences with half the attention; the other half is holding up a mobile telephone, recording the performance. The gathering becomes half-experienced, half instant archive.

You can see this in any number of events. I've even seen people doing it at the opera house, once at a performance of an opera I wrote the words for. (I can tell you, that woman's going to think twice before she records a live event in the future).

There are two issues here: the first is that because of the divided attention, the experience of absorption and surrender becomes harder to come by. Whether on the dance floor, at a drama, listening to music, or even in the lecture theatre, it is harder to be swept away because of the sheer number of people recording the event as it goes along. In the Hermitage Museum in St Petersburg last year, I saw any number of tourists enter an incomparable Matisse room with a camera already held up before their face; they walked around, and left still with the thing raised. What had they seen? How could they ever surrender to the vast magic of Matisse in full flood?

Because of the ubiquity of the personal camera, people do sometimes think that it's a normal way to respond to performance of any sort. But comedians are absolutely right to insist on the all-or-nothing approach.

You either pay to see a comedian live, and experience a dangerous live experience; or you buy the recorded experience that the comedian thinks represents their work at its best. The word "bootleg" is not much heard any more, because we're all at it. But Sarah Millican is absolutely right. It's theft, as much as if you went into Waterstones and photocopied every page of a new novel before putting it back on the shelf and walking out.

It's a choice between the authentic, judged, full-quality experience and a version of scraps and fragments. A theatre company is currently staging a full, word-for-word rendering of The Great Gatsby, to packed houses. There is a hunger for that and, I dare say, for the full text of great novels left unperformed, too.

Do you want a great novel in full, or do you prefer a quick dash through a classic, omitting almost everything but the bare plot outlines, like the BBC's recent Great Expectations? Do you prefer to pay to sit and experience a terrific comedian at the top of her form, or would it do just as well to say to your best friend – "Oh, if you're going, remember to film some of it. I'll look at it when I see you Thursday?"

Every sign is that people, on the whole, prefer a full, rich, absorbing cultural experience. They like to engage with complexity and the unrepeatable experience. They want to say, "You should have been there", not "This is what it was like, look." And, in most cases, they don't know what it was like. They weren't there. They were behind their mobiles, holding them upwards like talismen.