The bust of Nefertiti has just had a CT scan! Under the famous portrait of the queen is another bust, in limestone. (the well-known one is in stucco)
The original shows an older, more mature Nefertiti, with more realistic features, including small wrinkle around the mouth and a slight "bump" on the nose. Check out the NatGeo site for a picture.
As to why such "airbrushing" was done, the most logical explanation is one in which the artist was intent on flattering the queen! (a wise political move!)

http://news.nationalgeographic.com/news ... cture.html