We see the world a work of literature is set in the way the author wants us to see it. Our only glimpse of the characters and their setting comes from the information the author willingly divulges, and even then it may be hidden so that only the more observant readers can see it.
In this respect, I agree with Abdou more than with Vicky and Amir. While we do not/cannot judge characters by their physical description, this does not necessarily teach us the stated lesson: when I begin reading a book, I already expect to learn more about characters as they are developed and tend to not judge them by their physical description unless an unusual amount of emphasis or explanation accompanies it.
An author's ability to withhold information or fool the reader, on the other hand, is really able to drive the above lesson home, in my opinion. The author can "fool" the reader simply by not revealing a character's thoughts, or even by using the already mentioned physical appearance for the same purpose: emphasizing it to make the reader think it is informative regarding the character.
The Lost Honor of Katharina bloom is a good example of this. While the reader knows that Katharina kills a journalist, they are lead to believe that she is reasonable and cool headed and that may believe that the murder was a result of a sudden circumstance or decision. However, it turns out that Katharina planned the murder beforehand. Had the reader had more of an insight into her thoughts (something he/she was denied by the author), then Katharina's actions may not have come as a shock.