how do Paul and Kropp react to the sight of the theater poster?why?

Paul and Kropp came across an army theatre poster. It is a poster of a beautiful girl wearing "white stockings and white shoes Paul notices that she is "well cared for , she certainly baths twice a day and never has any dirt under her fingernails". The boys themselves are constantly filthy and worn out. They are so far removed from anything clean. Beauty, romance and the real wonders of the opposite sex remain a mystery to them and they wonder if they will ever be able to experience this.