Miller uses descriptions of characters’ physical appearances to imply the kind of job that they ought to have. Happy and Biff, for example, are supposed to be strong, built men who look like they’re cut out for manual labor. This reveals the conflict between what they are made and want to do (work with their hands) and what they are forcing themselves to do (office work). In comparison, Charley and Bernard are relatively nerdy, un-athletic guys, perfectly suited and happy to be in an office setting.
The characters’ tone of voice reveals much about their inner feelings and their manners of dealing with stress. Biff is extremely sarcastic; he feels bitter about his past and his relationship with Willy. Generally everything that comes out of Happy’s mouth is positive; he’s always trying to smooth situations over and be a peacemaker. Willy is abrupt and his tone changes quickly from admiration to anger or bitterness; he is internally conflicted.
Each of Miller’s characters are defined by the way they respond to the tense environment of the play. Willy and Happy consistently react with denial to anything unpleasant. Biff responds to tension very emotionally. Linda reacts to crisis with an extremely even temper, and Charley with extreme practicality.
Many of the names in Death of a Salesman have symbolic and ironic significance. The name Happy, for example, is suggestive of contentment (that was the most obvious statement, we know). As we all know, Happy is extremely unhappy. In addition, the last name Loman, which is almost exactly "low man," is ironic in light of Willy’s high aspirations. Names are further emphasized by Willy when he insists that Howard is indebted to him because it was Willy who named him. But in keeping with the irony of names and naming, Howard will not accept Willy’s claims over him and even calls Willy, his elder, "kid."