I wonder what the context of this postcard is. In 1940 I can't help but believe it would have been a pejorative. Maybe with the mounting tensions in Europe this was supposed to shame men into joining the army rather than waiting to be drafted.
NO, this was calling women in pants "men." Same problem with this blog, they "think" skirts on men make them "feminine." Not necessarily--Roman soldiers, Alexander's Macedonians, all wore skirts, skirts, and skirts. Not womanly, soft, sissy, soft, girlish nor effeminate. Greek army today has unit of men in pleated skirts, blouses, and embroidered vests. The attire is MASCULINE because THEY wear it and skirts/pants are SEX NEUTRAL. Too bad people insist on reasoning by mere association--it yields so many false conclusions. Also see "Hebrew Warriors" on Discovery Channel---all men in SKIRTS. Bible NOT against men in SKIRTS!