Mason is right when he says that the shape is important, but no-one has yet succeeded in making the shape close enough to even make a character recognisable without strong cues (like a uniform). The tex just makes up for what the modelling lacks, which is usually a lot. If I tried to use my source photo with the other texture, as Darth suggests, I think it would come out the same because the Poser head dominates. However, if I used Mason's head model, which is much better than mine, tweaked it a liitle to exactly match the photo - we'd really be getting somewhere.