Mr. Smith, like all the characters in the play, is pretty one dimensional. He comes off as a stuffy middle-class Englishman and his character doesn't get much deeper than that. Mr. Smith speaks mostly in clichés and constantly makes dull, superficial observations. For the most part, he doesn't seem to have strong opinions about anything. All in all, Mr. Smith doesn't have too many distinguishing characteristics. Ultimately, he is quite generic and pretty interchangeable with Mr. Martin. This fact is highlighted when at the end of the play he is literally replaced by Mr. Martin.