This is the army, Mr. Jones,
No private baths or telephones.

The couplet delivers a brisk, comic reminder that military life strips away civilian comforts and social privilege. Addressing “Mr. Jones” (a deliberately generic name) suggests the line is aimed at any recruit who expects special treatment. By listing “private baths” and “telephones,” the speaker evokes the small luxuries and personal autonomy that disappear under army discipline, where resources are shared and communication is regulated. In Irving Berlin’s idiom, the humor is not merely mocking; it functions as morale-building realism—an invitation to accept the egalitarian, no-frills conditions of service and to adjust one’s expectations accordingly.