The moment’s genius is down to Killing Eve’s season one costume designer, Phoebe de Gaye, who nailed the ever-evocative juxtaposition of opposing fashion aesthetics: stomping leather and feminine fluff. In the process, she also plugged into a generation’s increasingly discombobulated relationship with its own femininity. In fact, Comer’s gloriously sweet-n-sinister Villanelle has been hawkishly watched since the first episode of Killing Eve, every quirky fashion ensemble slavishly dissected and posted with Insta-accolades and designer brand names; her Dries Van Noten trouser suit, her Chloe mint silk blouse or velvet jacket, her Burberry sky lace dress, Lanvin shirt, Prada trench coat, Mui Mui frocklet. Fashion media from The Cut to Vanity Fair have also run headlines akin to: ‘‘How to get Villanelle’s style for less’’, ‘‘Where to find Killing Eve’s Killer outfits’’, ‘‘Why the fashion on Killing Eve is its own delicious subplot’’. Et cetera. Obviously she’s a fantasy because of what she gets up to, but [the audience] must kind of understand her and relate to her too. Charlotte Mitchell Readers have inhaled exhaustively researched lists of echo-options for Villanelle’s eclectic wardrobe. An echo of the marvellous Molly Goddard frock, for example, could be had for $60 at ASOS. Her Phillip Lim floral bomber, $88 at Everlane. Her Prada vintage trench, $50 at Uniqlo. And so on, ad fashioneum. Not since Sex and the City costumer Patricia Field patched Sarah Jessica Parker’s character Carrie Bradshaw together with op-shopped tutus, tighty-whiteys and Manolo Blahniks in the 1990s has a comparable blip registered on fashion’s timeline and, more importantly, trickled down to so many eager mere mortals.

Two decades after Sex and the City, however, the amplifying effect of social media is a new twist: global rocket fuel for the phenomenon, as costume designer for Killing Eve series two, Charlotte Mitchell, is well aware. When she replaced de Gaye, Mitchell tells me from London, she knew the writers’ and producers’ yearning for a repeat of ‘‘the Molly Goddard moment’’ – for a thousand such moments – was inevitable. ‘‘I knew it, but I also knew it couldn’t just be gratuitously written into every episode.’’ ''So cute she’s sinister'': Villanelle is dressed to kill in an Amsterdam brothel in season 2 of Killing Eve. Credit:ABC Such clockwork artificiality, she reckoned, could diminish the resonance Villanelle had with real girls and women. ‘‘We needed to find those moments slowly, in Villanelle’s quieter times as well as her quirky loud moments. We needed to remember we’re telling these stories for real people. Villanelle still had to be accessible. Obviously she’s a fantasy because of what she gets up to, but [the audience] must kind of understand her and relate to her too.’’ Mitchell is a graduate of fashion’s top college, Central St Martins in London, a one-time designer for Fiorucci in Melbourne and, after slipping sideways out of fashion into costume design, a veteran of top BBC productions such as Poirot, Doctor Who, Endeavor and Harlots. Her specialty is costume infused with a sense of relevance and modernity, even if it is a period style. ‘‘It’s about keeping it real,’’ she says. ‘‘It’s easy to stray into caricature if you can’t get that right.’’

She picked Villanelle’s clothes for their subtle visual links to the assassin’s personality and moods. It wasn’t simple. Villanelle is brattish and playful, prone to kiddy sulks, has a tendency to boredom and, with the fat packets of money she gets for every murder, shops like any cashed-up Millennials, honing in on trendy brands one minute, picking up pretty little luxuries – unrelated treasures – for their own sake the next. ‘‘We’ve heightened her reality,’’ Mitchell says. Such as it is. ‘‘So every piece looks utterly natural, not like it’s been chucked in there because it’s in the script.’’ Jodie Comer channels Oxford chic in a scene in which Villanelle confronts Eve's husband. Credit:BBC America Mitchell designs, creates, and shops constantly for those intuitively right pieces: the plush cherry fur coat by Emporio Armani, for example, that Villanelle pops on to push a woman under a bus. The shoulder-grazing vintage Lacroix earrings she wears for a quiet, but extravagantly glamorous pre-murder moment in the middle of Amsterdam. The flirty Miu Miu wrap frocklet for her sunny ‘‘date’’ with a boy she later, quite accidentally, poisons. The circa 2012 McQueen black silk gorgette dress she wears with an elegant tick of lace over her face (Mitchell’s original design), to simultaneously murder and mourn her nemesis. ‘‘I go around the shops, not trying to create a particular look but to find individual pieces that just stand out to me,’’ Mitchell says. Her bower-bird tendencies have to replicate Villanelle’s. ‘‘Then I go back to my office, do mood boards, start creating a feeling, and something starts happening, coming together ... ’’

When the scripts come in, often with wardrobe descriptions stipulated, Mitchell shuffles her concepts and collaborates closely with the writers, producers, actors and director, thrashing them into precisely the right scenes and refining until they’re layered with fashionable subtleties and utterly believable. ‘‘They [the audience] can then understand Villanelle,’’ she says. ‘‘She’s eclectic. She loves luxury and designer fashion but she also hams it up, adds humour, makes it her own.’’ Villanelle’s Millennial-esque flair for the dramatic is also usually kept within believable bounds by Mitchell. However, for one showy murder in Amsterdam, special dispensation was deemed appropriate. ‘‘The director wanted a sort of vaudeville theatrical piece,’’ Mitchell recalls. ‘‘She wanted a dirndl [think Oktoberfest costume], which I couldn’t really understand at first but, she said ‘Think of a Japanese manga character; really really cute, so cute she’s sinister’ and it worked brilliantly.’’ In the murder scene Villanelle, in puffy pink tutu, dirndl and cartoon pig mask, strings up her victim in the window of a street brothel and murders him, abattoir style, for a cluster of, at first curious, then puzzled, then horrified passers-by.

Mitchell does occasionally shop with Villanelle’s most intimate ally, Jodie Comer; ‘‘just not very often because it takes a hell of a long time and she’s always busy learning her scripts or doing her dialogue coaching’’. (Comer perfected half a dozen flawless accents for the Villanelle character.) ‘‘But it’s in the fittings that [outfits] get to feel real or not,’’ Mitchell says. ‘‘You can tell when something’s really going to work, really feel real. I’ll say [to Comer]: ‘Walk around, put your hands in your pockets, how does it feel?’ And you can see, she sort of has that strut and looks great, she’s claiming it. But if she’s not, then it’s, ‘Take it off, you’re not owning it, it’s not going to work’.’’ Killing Eve series one and two are on ABC iview. A third season has been commissioned.