There's a reason why Jack is always smiling

Forget subliminal shadows in well-defined musculature. Strips like this is why the Comics Code Authority was created. Yet these funnies served an unintended purpose beyond sales-inspiring titillation, giving the young access to some material that provided, albeit through an unrealistic filter set in place by mostly old men, education in what for the era were proper gender roles and societal expectations.

Smilin' Jack story re-printed in the Dell title Popular Comics #101 (May 1946).