Basically this is Costume Porn applied to a cape (or robe worn like a cape), where that piece of clothing is expensively decorated. This was common throughout history, for both men and women, as capes of various kinds were a common clothing item, and clearly visible due to their size. Thus a grand cape would easily be a way to show off one's wealth and social status. In fiction, it's a way to [...] [tvtropes.org]