Rob Kardashian on first seeing Caitlyn Jenner: 'Who is this woman?'

Caitlyn Jenner, formerly Bruce, made her big debut on Monday on the cover of Vanity Fair evoking reactions from family, friends and other celebrities showing their support. Rob Kardashian may have been the most shocked off all as sister Kim Kardashian revealed her brother didn't recognize his stepdad when she sent him a picture.

"It was so funny because all the girls, we knew that Caitlyn was shooting this but my brother had no idea," Kim told Access Hollywood at the CFDA Fashion Awards. "So I sent it on a mass text to everyone and my brother was on it and he goes, 'Kim, why are you sending me this? Who is this woman? And why do I care?'"

Rob Kardashian didn't recognize Caityln Jenner at first Photo: Getty Images

The reality star, who had just announced her pregnancy the same day, informed her brother who was in the photo. "And I was like, 'Rob, that's Bruce! That's Caitlyn,'" she added. "And he was like, 'Oh my god, she's beautiful!' And then he called her and they had a lovefest and it was so cute. But the moment was so funny."

Another hilarious reaction came from actress Jessica Lange whose name began trending because of the uncanny resemblance between her and Caitlyn. When The Daily Beast told the 66-year-old about comparisons on Twitter, her response was heartwarming. “That’s so wonderful. Well now I’m going to have to look for that picture,” she said after being informed what trending meant.

Jessica Lange has been compared to Caitlyn Jenner Photo: Getty Images

Many other celebrities have spoken out in support of the former Olympian taking to social media to share their thoughts on seeing Caitlyn. "CAITLYN!!!!!!!!!! Love this. So happy for her," tweeted Kerry Washington. Ellen DeGeneres said she hoped "we can all be as brave" as her. Maria Shriver said the cover made her stop, adding: "You go Caitlyn." Even President Barack Obama got in on the action retweeting Caitlyn's first tweet, saying: "It takes courage to share your story."

Caitlyn Jenner revealed her new look this week Photo: Vanity Fair/Annie Leibovitz

Many of the young fashion posse, who are close friends with the Kardashian clan also backed the world's newest and most glamorous transgendered woman. Model of the moment Gigi Hadid, who is friends with Caitlyn's daughter Kendall Jenner, tweeted: "Hi Caitlyn you are beautiful."

The 'go Caitlyn' camp also includes Miley Cyrus, Lena Dunham, Emmy Rossum, Sam Smith and Victoria's Secret beauty Lily Aldridge.

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