It doesn't require a 'perfect' size 6 to carry it off. It doesn't require thighs the size of a sparrow's and it doesn't require high heels and red lipstick.
It merely relies on nonchalance, the ability to wear something with a certain crumb of style, shrugged on with a pair of masculine brogues, barefoot and plainly beautiful. It is, in short, utterly undemanding - unlike its schoolgirly counterparts.
Even among the gymslips and tiny, flirty dresses which Gianni 'Mr Glamour' Versace sent down the catwalk for summer, modest ankle-skimming, mysterious dresses (admittedly, some split thigh-high) were included. Weightless layers of the finest chiffon swirled in arabesques about the curvier bodies of Claudia Schiffer and Helena Christensen. For Versace knows his customer: he knows well what some of his ageing rock stars' wives will wear and what they won't wear. Short is not sweet and flattering for all.
However, this grown-up approach does not sacrifice sweetness, for these liquid dresses have an innocence and freshness of their own. They are feminine in a soft, less aggressive way, appealing because they conceal: they do not rely on a gawky display of awkward flesh. They are so easy to wear, they feel like sloppy, well-worn favourites - there is a hand-me-down, heirloom quality to these dusty dresses, evocative as they are of the flea market and the jumble sale.
They are also as much about the prints as the relaxed shape. Here, they are mainly abstract: the Versace print is a complex paisley, the others are dreamily indecipherable.
Elsewhere on the high street Dries Van Noten's shift dresses, inspired in part by Indian saris, have photo prints of cabbage roses strewn across the fabric. Joseph's floaty dresses use simple florals which would look equally at home on a Thirties tea set.
But flowers are not compulsory. Jean Paul Gaultier has printed his apron-wrap around summer dresses with chunks of Japanese text.
Whether you are prepared to pay the price for a whimsically expensive Versace or spend a more reasonable two-figure sum on a chain-store version, the dress is this summer's essential. It will accompany you on holiday, for it can be crumpled up into a bag (even at pounds 1,860) and worn with your oldest cardigan, fading and frayed at the edges. Easy isn't the word.