Shaw presents the satire of his play through his dramatis personae. Each character represents a part of society and/or a worldview that Shaw satirizes by pointing out its follies, using irony as his primary type of humor. Reverend Gardner represents the hypocrisy and powerlessness of organized religion. When Frank invites Gardner into Mrs. Warren's yard to meet Vivie, he objects, saying, "not until I know whose garden I am entering." The ironic symbolism is that he has had an intimate relationship with Mrs. Warren outside of marriage; he is not nearly as circumspect as he portrays himself. He also is obviously powerless against his son's disrespect and rebellion.
Frank represents the young males of Shaw's time who were worthless pleasure seekers. When Gardner tries to discourage Frank's interest in Vivie as a potential wife, he says, "Brains are not everything." Frank replies, "No, of course not: there's the money." The ongoing joke of Frank wanting to marry for money satirizes both the tradition of women marrying for money and the ironic twist that men of that generation who had no means of making a living because they were inept would have to find a wealthy woman to support them. Frank's hedonism is also satirized; his physical attraction for Vivie is not dimmed in the least by the revelation that she is his half-sister.
Crofts represents the part of society, both institutional and individuals, who profited from prostitution. The fact that Crofts maintains a respectable reputation despite making his money from abusing women satirizes the men who got their physical desires satisfied by prostitutes but presented a false moral front to their society. Only the most despicable irony lends humor to his character as he describes to Vivie how respectable she would be as his wife. More humor, aggressive humor, is achieved when Frank threatens to shoot Crofts "accidentally."
Obviously Mrs. Warren satirizes a society that provides so few options to women that they are driven to prostitution. Yet she is not dealt with sympathetically, either; her twisted morality is put on display.
Shaw uses Praed as a means to satirize Aestheticism. As harmless as Praed seems to be as a follower of the "Gospel of Art," he is nevertheless completely useless, offering no solutions to the real problems Vivie or society faces. Rather, he is on his way to tour the continent, showing how Aestheticism was just a way of escapism that had no lasting beneficial impact on the culture.
Vivie herself serves to satirize the lifelessness of the intellectual career woman. She hates holidays and doesn't care for romance or beauty. At the end she insists she must be treated as "a woman of business, permanently single and permanently unromantic." Her "babes in the woods" scene with Frank is creepily humorous because of the dramatic irony: the audience suspects Frank and Vivie are half-siblings, but the characters don't know it themselves at that point. Later when they find out, Frank suggests that they go get "covered up with leaves again," and Vivie cries, "Ah, not that, not that. You make all my flesh creep."
Shaw uses mostly irony, and particularly through the character of Frank, to add humor to this play, a play that satirizes organized religion, a society that pushes women into prostitution and then profits from it, Aestheticism, hedonism, and workaholism.