In Disgrace, occupations aren't just about what you do, but also where you come from. We learn almost immediately that David is a professor at Cape Technical University. He sees himself as a professor of the old-school variety – a scholar who lives mostly in his own mind, pursuing his research interests and writing books on obscure topics like the love life of Byron. He's not thrilled that in order to maintain this lifestyle, he has to teach courses on less "intellectual" topics like Communications to students who would obviously rather be anywhere but his classroom.
On the other hand, the other major characters that we encounter have occupations belonging to the more rural setting of the Eastern Cape. Unlike David, whose work stems from his brain, their work relies on their hands. Bev works at the animal clinic. Her job is totally voluntary, but she throws herself into it, both trying to heal the animals that she knows she can help and to ease the suffering of those she can't help by putting them to sleep. Lucy is especially crunchy – she works the land, growing vegetables to sell at the market. She also runs a kennel from her home. Petrus takes care of the dogs (he creatively refers to himself as the dog-man) and helps Lucy out with prepping for the market. By paying attention to what people do for a living, we learn more about the culture shock that David goes through in moving from the city to the country.
Now, we're not saying this is true in real life, but in Disgrace, people from the city tend to be a little easier on the eyes than people in the country. David himself is described as being a silver fox: "with his height, his good bones, his olive skin, his flowing hair, he could always count on a degree of magnetism" (1.34). In contrast, in the country we get men like Bill Shaw, who is "squat" with "a beet-red face and silver hair and a sweater with a floppy collar" (8.55). Note how Coetzee takes the effort to point out the same aspects of both Bill's and David's appearances – height, skin tone, sexy or un-sexy hair.
Interestingly, when David moves to the country, he loses his good looks. No, he doesn't become chubby and ruddy like Bill. Rather, David's injuries from the attack on Lucy's house essentially erase the physical features in which he once took so much pride. When David is covered in alcohol and set on fire, his ear is weirdly disfigured and all of his hair is singed off. David doesn't necessarily take on the physical characteristics that other people of the country display when he moves to the Eastern Cape, but his city appearance becomes a thing of the past.
Coetzee also uses physical appearance to characterize the differences between women in the city and the country. Melanie is quite a looker:
She is small and thin, with close-cropped black hair, wide, almost Chinese cheekbones, large, dark eyes. Her outfits are always striking. Today she wears a maroon miniskirt with a mustard-coloured sweater and black tights; the gold baubles on her belt match the gold balls of her earrings. (2.5)
Melanie is not only physically attractive, but you can tell she's invested in her appearance by the painstaking attention to detail that her outfits display. In contrast, Lucy and Bev are both heavier women; Lucy goes around barefoot, while Bev doesn't seem to devote any of her attention to her appearance.