Glad the links might be of use. :) 

Usually, I find that only using a picture, especially in a detailed bio, feels sort of like a cop-out. Not that it can't work just fine without, but a picture, while it might be worth a thousand words, just can't tell you the same things those paragraphs can. Unless it's got everything in it from mood and posture, a fitting expression and just the right clothes, there's more to a character than their eye colour or length of hair and real life pictures, or portraits, don't always make that obvious. 

So, at least for me, when I make a character based off a picture, I'm not thinking I like their look and adding on everything else, I'm usually attracted to the person's expression or their actions, or placement within the picture and its the personality they're affecting that I want as opposed to the specific appearance. And that is definitely something that someone else could misinterpret just from looking at the picture. Or, not misinterpret, but see it differently. Of course, in real life, misinterpretations happen all the time, so having the chance to explain what a particular expression on my character's face means can be both a blessing and a curse, with no fun, organic misunderstandings between chars.... Aaaand I'm rambling...