Negative space defines and emphasises the main subject of a photo, drawing your eye to it. it provides "breathing room", giving your eyes somewhere to rest and preventing your image from appearing too cluttered with "stuff". all of this adds up to a more engaging composition.
A because allows you to scrutinise every part of the image before judging it
It can help others go through the 4 stages of art critism like judge, interpret, decribe and analyze. You can not do that if you have nothing to analyze about the art work
