hmm i think the main difference is the lack of concealer
of course NO ONE has "perfect" skin, everyone's got those little blemishes and such

i'm kinda shocked at jessica alba though
HER SKIN IS SO FLAWLESS!
(from what i can judge by the picture)

---edit---
LOL I JUST SAW THE OPERA PICTURE
she looks like a man!
http://bp0.blogger.com/_8BzxXSocQZU/...rahWinfrey.GIF