Caitlyn Jenner's stylist talks about keeping the Vanity Fair shoot a secret

There was an internet frenzy when Caitlyn Jenner, formerly known as Bruce, made her debut as a woman on the cover of Vanity Fair on Monday.

Now, Jessica Diehl, the stylist behind Caitlyn's stunning look has spoken about the top-secret assignment, explaining how she managed to keep all details under wraps – including telling her colleagues that she was shooting Barbara Streisand.

Chic between shots @caitlynjenner ❤️ #callmecaitlyn #vfbehindthescenes @vanityfair photo credit : @kmacnyc

A photo posted by Jessica Diehl (@jdiehlpoynter) on

"My poor office thought we were doing Barbara Streisand!" she said in an interview. "I just couldn't think of anyone tall. And I don't even know if Barbara is tall, but in my mind she was tall, and so that just seemed right!"

The preparations, which the magazine described as "James Bond-esque" also included, according to Jessica: "being discreet and shopping – a lot of which we did online. We talked to no one. Literally, the people here at Vanity Fair did not know. Three people in the fashion department knew, including me."

Jessica didn't have much time to style the shoot, and wasn't able to put in the preparation she normally does for a cover. "Normally we go to, I don't know, Valentino or Armani, and say we are shooting a cover and ask if they can give us some clothes [to borrow]," she said.

"For this, I had to go into stores incognito, so to speak – not like anyone would know what I looked like anyway – and buy stuff. That was actually what was fun. It was like Vanity Fair: Off The Rack."

The stylist praised also praised Caitlyn's athletic figure.

"She has a fantastic physique," she said. "It's just a totally well-taken-care-of physique. She's an athlete, so the muscle tone is incredible. She's slim, and her proportions are very easy to dress."

Thanks to her clothes-friendly figure, the fitting wasn't a difficult task. "We had basically a three- or four-hour fitting. I have to say, out of that three- or four-hour fitting, there were only two things we did not like," she said.

"Everything looks good on her. That just doesn't happen."

Jessica revealed that Caitlyn made a conscious decision to go down a more classic route with her styling, steering away from the Kardashians' fashion-driven looks.

"Coming from a very fashion-forward family, we sort of thought that the nicest thing to do was to focus on style over fashion," said Jessica.

"Nothing too bling or too shiny. Kind of keeping it more in the style arena rather than hardcore fashion arena."

Jessica visited Caitlyn at her Malibu home and the pair sought inspiration from vintage photographs of old Hollywood stars like Lauren Bacall and Faye Dunaway in The Thomas Crown Affair, as well as pictures of Jackie Kennedy.

Talking about Caitlyn's personal sense of style, Jessica revealed that "she's all-American in so many ways. She has certain ideas about what she feels great in. But those ideas are still forming and taking shape.

"It's not always smooth sailing, but I think she has a pretty good idea of what makes her feel good, and those are classic silhouettes."