Originally referred to well-bred young women of prominent families (名门闺秀 míngmén guīxiù 'daughters of distinguished houses'). On modern Chinese social media the term often carries a sarcastic edge, like calling someone an 'Instagram socialite'.
memory
名 (míng) 'famous' + 媛 (yuàn) 'beauty/young lady' = a famous beauty. The character 媛 contains 女 (woman) on the left.
