Popsugar Fashion Naomi Watts Naomi Watts Diana Movie Costumes | Pictures Exclusive: How Naomi Watts Became Princess Diana February 9, 2014 by Randy Miller First Published: September 25, 2013 View On One Page Photo 1 of 14 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 1 Julian Day on Diana In this exclusive clip, the film's costume designer, Julian Day, explains how he set about dressing Naomi Watts as Princess Diana. Previous Next Start Slideshow Naomi WattsFashion NewsTod'sChopardPrincess DianaScreen Style