Although the article is interesting, I think one of the comments is much more "to the point":
What gets me about this ad is that no one understands why the women basically described themselves as trolls and the women they were talking to as goddesses. They're being filmed. They know it, and they know it's being put up somewhere. They don't want to be seen as having an over-inflated ego - they know exactly how it's going to look to the watcher if they describe themselves as more beautiful than they are. They have to have had an idea of what the guy is doing, which means they're going to know there's going to be a sketch hanging next to their real face. Wouldn't you want to look nicer than the sketch?
As for the women they're describing. When a stranger asks you what you think of their hair, have you ever said, "I hate it"? Again, they know that someone is sketching. They describe the other woman in the prettiest terms they can.
This isn't a deep look into their feelings about their actual looks, it's an exercise in self-marketing and politesse.
Yes that was pretty obvious looking at the Ad. People are very less likely to criticize other people's appearance before a camera especially in a country like US where people tend to be ridiculously politically correct.
It was also a commercial. Commercials also magic soap bubbles and talking birds.
Even assuming they did the commercial straight up with "real people", and the sketch artist wasn't in on it, there could have been a huge file-drawer effect of the 200 people/takes where the pictures came out the other way or just the same or just too bland to work in a commercial.
http://thelastpsychiatrist.com/2013/05/dove.html