One point of comparison between A Woman on a Roof and A & P is the theme, in both stories, of individuality in which there are some things alike and some things different. In Doris Lessing's A Woman on a Roof, Tom, being young and working with grown men, is unsure of his individuality and insecure. The incident with the sunbathing woman prompts him to step out of his insecurity a little bit and attempt to protect the sunbathing woman from the energetic admiration and ogling of his co-workers; never mind most of his efforts at protecting her rank with a sheepish embarrassed and apologetic grin. It's the thought that counts. In the end, Tom acts on the fantasy relationship his dreams at night have built up between him and this woman and he takes up courage and crosses--a long metaphorical cross into the unknown--over to her building and goes out on her roof imagining a warm and welcoming conversation befitting of his dreams instead of the cold rejection he receives. Tom's individuality, which was beginning to grow and thinking of blooming, is crushed.
In John Updike's A & P, Sammy has a pretty confident sense of individuality and is secure as is witnessed by his calm confidence at his job. When the swimsuit clad girls come into the store--expressing their individuality--against the rules of the store, Sammy gladly gives his mind a rest from his clerking duties to follow their shopping progress. He begins to feel a real connection with these peerless beauties and when Lengel upbraids the girls for their attire and sends them packing, Sammy, feeling like they and he both recognize him as their champion defender, crosses his own path into the unknown and speaks up in their defense. The result is that the girls walk out, completely unaware of any great obligation to Sammy and Sammy walks out on his job. His individuality is crushed because the outcome he had imagined, conjured up by his own fancy, fell as flat as Tom's imagined outcome conjured up from subconscious fancy.