The design featured a plunging V-shaped neckline, delicate capped sleeves and intricate lace panels at the waist.
Its cinched, embellished belt and full chiffon skirt gave the dress a dramatic fluidity, while the transparent back added an unusually bold twist for the royal.
The back was striking - a sheer panel delicately scattered with sequins and finished with a row of covered buttons running down the spine.
In 2012, when she first wore the gown to an Olympic concert at the Royal Albert Hall, Kate swept her hair into an elegant updo, letting the transparent back and plunging neckline take centre stage - a quietly daring moment that reset expectations for royal eveningwear.
That teal appearance now feels like the blueprint for her signature style today: quiet sustainability, purposeful repetition and an emphasis on craftsmanship over novelty.
It’s a strategy she has continued to own, as shown on Thursday when she re-wore her grey Prince of Wales check Bella Freud suit at Royal Air Force Coningsby.
Her decision to bring back the teal Jenny Packham gown years apart was an early signal of a fashion philosophy rooted in longevity rather than instant impact.
Fast-forward to the present and that instinct has matured into a polished uniform of muted tailoring and repeat staples.
By leaning on subtle hues and timeless cuts, Kate is shaping a royal style that highlights her work rather than eclipsing it, setting a fresh template for modern monarchy dressing.