See the problem with the faces showing is privacy. I know many girls that wont see a certain client, or worry about running into career-/school-related folks, family members, certain age groups, etc. With a camera and a monitor, (or a few quick Q's to the girls who've already 'paraded') we are able to deter some awkward moments.
Could you imagine, a girl has a corporate job and her boss comes in and sees her face in a book! OMG I'd be mortified!
Besides, a book is so superficial! The good side of the meet-and-greet is personality. Seeing if you feel a spark, a click, a throb in your c***!!