I watched Zoolander a while ago for a comedy jolt to start my day. Anyways, I discovered at IMDB that among the celebrity cameos on the show included designers and whaddya know, makeup artists and hairstylists. Among them were cameo appearances by Frederic Fekkai and Kevyn Aucoin.
(image from beautynewsnyc.com)
Celebrity hairstylist Frederic Fekkai has been known to style and primp the tresses of Debra Messing, Kim Basinger, and supermodel Claudia Schiffer. He also has his own hair products line, a much in-demand luxury product internationally. He has also appeared as a guest in America's Next Top Model when the models had their makeovers done.(image taken from stylelist.com)
Of course, we all know the late Kevyn Aucoin, whose books Making Faces and Face Forward are considered beauty bibles of every makeup artist and makeup fanatic. He did Gwyneth Paltrow's makeup when she won the Oscars for her role in Shakespeare in Love, and he has done makeup for several other celebrities like Madonna, Tori Amos, Winona Ryder, and Christina Ricci. My favorite was how he transformed Gwyneth Paltrow to James Dean.
It wasn't a full shot but they did appear for a few seconds as Derek Zoolander's (portrayed by Ben Stiller) Derelicte hairstylist and makeup artist respectively. I wasn't able to find a screenshot online but I took a picture of it while I was watching it on TV:sThat's Frederic Fekkai's hand primping up a Derelicte'd Derek Zoolander (Ben Stiller)
Here's a profile of Frederic Fekkai and the back of Kevyn Aucoin. :) This was the scene where Derek Zoolander gets primped up before the Derelicte Fashion show and he confronts his manager Maury Ballstein (Jerry Stiller). It's just a quick cameo appearance so better not blink to notice.
Of course, they were credited at the movie credits and at IMDB.