It's not news to anyone that branding, fashion and celebrity are three big drivers behind the appeal of social virtual worlds, especially those geared at younger folks. Users want to be able to dress their avatar in big-label brands, and virtual worlds users actually embrace advertising because it enhances realism. Finally, the way virtual worlds permit people to create better-than-the-real-thing versions of themselves and their lives, if they like, is part of its appeal -- fame and glamour are possible for anyone.

While visiting consulting group Kzero's site to check out their growth projections for virtual worlds, I happened to see their display for the latest campaign they built for L'Oreal Paris. They created makeup skins for each of the cosmetic line's celebrity looks to be worn by Second Life avatars, and to demonstrate, they showed panels of the Second Life celebrity looks alongside the real ones.

An intriguing conundrum is revealed -- the difficulty in emulating real faces in Second Life and other avatar-based virtual worlds. If a celebrity is the "face" of your campaign, that might be a challenge to translate. It seems that Kzero only skinned the makeup looks and not the celeb faces, so it's not an issue for users who want to adopt those color schemes. But for other display ads, will a virtual Scarlet Johansson have the same draw for users in the virtual world as she has for the real world if users can't necessarily recognize her?

Try and test yourself! Here are the celeb faces from Kzero's campaign -- can you tell which stars they are? Answers are after the jump -- but if a famous face is your branding and it can't be recognized in the virtual space, something's lost in translation, isn't it?