to ‘show your stripes’ is an idiom, meaning to show your true self. This is presumably related to the idiom ‘a tiger never changes its stripes’, which means you cannot change your true self.

While an idiom is a literary device, this idiom was most likely inserted as part of the translation to modern English (I don’t think the ancient Greeks would have used such an idiom..) Therefore, I would be hesitant to overanalyse this or use it in thematic analysis.