What is the fine-grained topic of the following text: Funnily enough, photographs of an immaculately-dressed post-partum Middleton always put me in mind of Britain during WWII, when red lipstick became an affirmation of dignity and the morale-boosting mantra 'beauty is your duty' was trumpeted on the pages of Vogue magazine. Only return the topic.
Post-partum fashion and beauty standards in relation to British WWII morale-boosting practices.