We all love a fashion show, and whilst this may not be the first airline to run a fashion show in the sky (we think Sky Europe were the first to do that in the modern Era), it certainly is the first to do a retrospective of their uniforms through the years. This was part of LAN Chile’s 85th year celebrations of serving Chile.
Onboard flight LA 634 between Santiago, Chile and Lima, Peru on the 12th March, fashion models that work with renown Chilean designer Manuel Rojas, showcased uniforms used by LAN’s flight crew throughout the 1950s, 1970s, 1980s, 1990s and today.
“The purpose of this vintage inspired fashion flight is to showcase LAN’s 85 years of history via a fashion show of cabin crew uniforms that represent more than eight decades of dedication to providing the best travel experience to our passengers,” said Andrea Rotman, Director of Marketing for LAN in Chile.
TheDesignAir 
Air Jamaica is the first carrier that comes to my mind which also organized fashion shows onboard (http://www.airliners.net/aviation-forums/general_aviation/read.main/2832233/). Stylish uniforms by the way from LAN.