I'll say that, as a judge, I can tell, and all the other (experienced) judges can tell when that box is opened and passed around for appearance . . . it's really an overall wow factor.
All of those little details contribute to the overall wow effect.
A comment that experienced judges offer to inexperienced judges is to judge appearance on just how much the presentation makes you want to eat that Q! Typically those entries that appear neat and organized score the highest. Then come the little subliminal things like abundance (more than six samples), shininess (gloss from the sauce), uniformity (similar size and shape) and so forth.
So, those are also the things I concentrate on when I am creating my turn-in boxes.
What not to turn is simply a minimum number of disorganized samples that appear to not be cooked enough. That's what not to turn in.