The Undershaft tradition is a tradition of foundlings, each Undershaft passing the firm onto a foundling who adopts the namesake of the parish—Saint Andrew's—where the firm's founder was discovered. This tradition demands Stephen's dispossession and Undershaft's estrangement from his family.
Within Undershaft's dogma, the foundling figures as a willful, self-made superman, a man whose thoughts and actions remain free from the chains of familial and class convention. The foundling is thus poised to surrender himself to the Undershaft name and carry forth its gospel of revolution, to destroy the old and inaugurate the new. For Undershaft, the tragedy is that the welfare state tames most of these men from birth, rendering them indistinguishable from the herd.
As Undershaft's successors, Cusins and Barbara assume the foundling's mantle. Cusins reveals the illicit origins of his birth, sheds his name, and becomes the next Saint Andrew. For Barbara, her foundling heritage means that she has no social class and thus comes "straight from the heart of the whole people". She represents the people universally and can thus serve their savior.
Certainly the most jarring shift from Acts I to II is the introduction of class- marked dialect, Cockney. Shaw's representation of the poor is at times fetishistic itself. Note, for example, how Rummy and Price are played affectionately for the audience's entertainment. Though they have long since pawned their winter clothes, the two are "stung into vivacity" by the cold, chattering vivaciously over their poor meal. Occasionally Price even breaks into a step dance.
Here one of dialect's primary functions is to set Barbara—the savior—against those who require salvation. Major Barbara figures as savior in the shelter through both her class and linguistic superiority over those around her. Barbara maintains her composure before all those around her through her impeccable dress and cool, professional manner. Moreover her return before the audience is the return of the proper, polished English of the act previous. In contrast, at his lowest, Bill's "voice and accent" will become "horribly debased." Barbara's dialect—that is, the dialect that masquerades as no dialect at all but "proper English," English as it should be—marks her as the Cockney's redeemer.
A number of objects assume crucial symbolic significance in the play. As Undershaft remarks, Cusins's ubiquitous drum, for example, symbolizes his relation to the Salvation Army. Like the drum, the Army is but an instrument for his Dionysian fervor.