Grace Kelly: Style Icon, V&A, London

The film star's crisp silhouette and little black dresses give way to gaudy Marie Antoinette confections

The pleasure of learning about a person through their possessions lies in the work of imagination required to connect maddeningly mute objects with the life of their owner. The flesh-and-blood reality of a long-dead monarch, for instance, remains elusive, but piecing together the material evidence available to us is all the more fascinating for that.

So what, then, can be gained from examining the personal effects of someone we already know (or think we do) – working backwards, as it were, from a familiar whole to consider the constituent parts? This is the approach that the V&A has plumped for with its current blockbuster Grace Kelly: Style Icon. Split chronologically into three parts – Actress, Bride and Princess – it traces the life, through her clothes and accessories, of the Hitchcock blonde who became European royalty.

It's a strangely frustrating exhibition. Ordinarily, the V&A is unparalleled in its recovery of distant ages, places and characters through costume (The Magnificence of the Tsars in 2008 truly lived up to its promise), but the woman at the heart of this show is somehow rendered more absent than ever by the clusters of headless mannequins which are sporting her dresses.

In part, this can be put down to a problem inherent to the subject. The reason so many adore Grace Kelly, the reason we might want to pore over the fabric of her clothes and inspect the minute scuffs on the Hermès handbag to which she gave her name, is that we fell in love with her physical presence on screen.

In the trio of Hitchcock movies (Dial M for Murder, Rear Window and To Catch a Thief) for which she is probably best known, Kelly's unique allure was her ambiguity – a potent sensuality at odds with the too-perfect-to-touch packaging. The clothes were important, essential even, but they were a foil to their flesh-and-blood wearer – and so, to see them lined up, immobile, and slightly macabre, is an inevitable disappointment.

The let-down is only intensified by the clips from Kelly's films and newsreels documenting her marriage, which intersperse the dresses. Standing before the little black dress that Kelly wears when the action takes a darker turn in Rear Window, or the Grecian number in which she lounges by the pool in High Society, just makes me want to go home and pull out the DVDs. Out of context, these are not spectacular examples of couture – merely well-constructed examples of pretty 1950s fashion.

Admittedly, there is something of the relic about a couple of outfits – the green satin gown she wore to collect her Oscar for The Country Girl, for instance, gave me the faintest ghostly frisson. But such moments will be few and far between – even for ardent fans – because what this exhibition is desperately light on is the apparel that most of us consider to be vintage Kelly. Don't expect to see her wedding dress, for example.

Beyond the handful of film costumes and outfits she wore in the build-up to her wedding, the larger part of the show consists of the French haute couture she favoured as Her Serene Highness – many of which are blowsy, gaudy confections halfway between Marie Antoinette and Little Bo Peep.

In fairness, it was the 1970s by then, and many of them were made for lavish charity balls in Monaco, but it's a reminder that the demure, irreproachably crisp silhouette she favoured as a jobbing actress went out of the window as soon as she got that Monegasque tiara on her head. When your social status is assured, you can wear what you damn well like.

The marked change in her clothing choices also makes me wonder just how strong a grip this "style icon" had on her own sense of style, and indeed on her sense of self. Much is now made of her influence on her costumes in the Hitchcock films, but you only have to look at the brilliantly codified wardrobes of Tippi Hedren in Marnie or Kim Novak in Vertigo to realise that the director could do just fine without Kelly.

On the morning I visited, the exhib -ition was packed, mainly with women exchanging reverent whispers about her innate "class" and the diminutive size of her waist – with the exception of one visitor, bending over a pair of rather well-worn pumps, who exclaimed in horror: "Such big feet!"

I found myself more in the camp of the bored-looking husbands, shuffling around, getting in the way in the woefully cramped gallery space. I wondered whether I ought to point out to them that the V&A has some excellent permanent collections and an outdoor café that is charming at this time of year.

To 26 Sep (020-7942 2000)