I think that IMDB should create a "looks like" function. This would be really useful because often i look on IMDB to find out who somebody in the film i'm watching is, however it doesn't turn out to be who i thought it was but it still bugs me as to who i was thinking of in the first place!
It sounds like you are requesting that IMDb implement facial recognition software to match the faces of celebrities. Developing such algorithms is probably beyond the scope of what IMDb can do. Fortunately there are third party vendors who have such software available.