Why, despite everything, I could never mind the Gap

Was it the party invitation that did the trick? Not really. No, it was the photograph of course. To you it may just be a baby. To Gap it may just be a customer. But to Rosie Millard it is a world superstar.

The woman in Gap Kids was quite clear. "There's a kid's party next Sunday in this branch," she said, wrapping up my daughter's white zip-up furry boots (size 0) and turquoise velour top, also zip-up, (size 3-6 months). "But it will be a nightmare, so come early." She gives me a special invitation. A Gift For You. "Have your child's photo taken and placed in a card modeled (sic) after our ads," it reads.

"There'll be food, and face-painting. I won't be there. I'm leaving", continued the assistant with a manner implying she was more than a little weary of dealing with zip-up furry boots, size Midget. "I'm off to Jigsaw. I can't wait."

There's no doubt that if my daughter's life continues as it has begun, she will be very spoilt indeed. "But you can't really spoil a four-month- old," I claim, nervously laughing while hiding evidence of her latest toy/dress/battery-driven plastic mobile from the inspection of the nanny. And a photograph in the style of a Gap advert! It would be so perfect. "I mean, she has the clothes, so a matching photograph; it's only proper," I say to my husband as we pack a supply of emergency nappies and bottles for our weekend exodus to Gap Kids in Central London a fortnight before Christmas.

The shop, if anything, is more crowded than the pavement outside. Which is saying something since half the Western world appears to have chosen this weekend to hit town. However, there ends the similarity. Everyone inside Gap Kids is toting a child. A woman of about 40 is prancing around in a fairy outfit. On a table are minute mince-pies and tiny biscuits shaped like holly leaves, presumably for children. Fathers are guiltily eating them.

I point to the lower ground floor; we need to go down to BabyGap, where instead of sweatpants for stubborn 10-year-olds, the rails are full of dear little velvet dresses for malleable tinies. Gap Kids deals with placating children who want to be in an adult world; BabyGap is an empire designed for adults who want their children to look like something out of Peter Pan. And this is where the photographs are being taken. "We don't take pictures of anyone over five, really," says the assistant. "They don't fit in the studio." And they're not half as sweet either.

We spend the obligatory pounds 15 (of which 20 per cent goes to Barnados, I remind myself) on a dear little snowflake jumper. And a matching hat, and socks. Well, by the end it comes to quite a lot more than 15 quid, but then you are helping charity, I remind my husband. We are then given a ticket and wait in line by the studio, where a man called Russell is taking the photos.

The studio has that all-white background into which the children are placed and which all Gap adverts have to have for that classless, timeless, placeless look. Will our daughter, Phoebe, look like one of those sweet children one sees on the side of a bus, laughing easily in their Gap hats and cardigans? I hope so. I also secretly hope a Gap talent-spotter in the shop might see how pretty she is and select her for a global campaign. I immediately banish the idea and think snobbish thoughts about awful pushy parents like the mother of Brooke Shields.

A rather sweet girl of about three is posing in the White Studio. She is wearing Dame Edna-like pink plastic glasses with no lenses in. "Come along, Florence," says her mother testily. The flash fires, and that's it; the Gap Free Gift amounts to one Polaroid Instamatic snap which is then inserted into a "advert" card for you to take away. And let's not have any nonsense about hoardings on the sides of buses. The card in question is rather small. But never mind.

Let's have a look at that Polaroid, I say to Florence's mother. I want to see how authentic this all is. The picture shows Florence beaming out of her pink plastic rims looking utterly sweet in that global village- esque manner that is so very Gap. "Of course, those glasses aren't necessary," says her mother, just in case I think her child suffers from some weird opthalmic condition necessitating lens-free glasses. "But she won't take them off. Loves them."

The session continues. There is Kylie, who screams all the time; Holly, who has to be placated with a special BabyGap hand puppet; Jason, who appears in a BabyGap leopard-print suit and baby Eva who is only eight weeks old, is propped up on a large pillow and clearly has no idea what on earth is going "EEEEva!" shouts her mother. Eva, by accident, waves a tiny paw. The camera fires. Another child transmogrified into the clean world of the Gap advert.

Christmas music is piped all around us. Gap employees stand brushing hair and wiping faces of children lined up for their photographs. I wake Phoebe up and we solemnly put her into her new snowflake jumper and matching hat. She is carried into the white studio and propped up on the white pillow. I call her name. She sucks her fist and looks vaguely at Russell.

Afterwards, I look at the picture of my child; and I can't help it. I wish the result could be used in a worldwide bus campaign, I really do. I know all about pushy parents, but she just looks so perfect. Just like an official advert for BabyGap clothes worn by over-privileged children. "Maybe we could turn the picture into our Christmas card," I say hopefully when we get home.