Why do girls post group photos where their friends look bad?

WHY do I see the girls I know on social media always posting posts with their 'besties' where the bestie looks bad compared to the poster? The poster will look super photogenic while their friend or group of friends look bad. Even when they're wishing their friends happy birthday, even us guys notice that their friend often looks noticeably worse than them in the photo. Do girls do this on purpose or is it something they aren't aware of? Are any of them even really friends with each other?

Why do girls post group photos where their friends look bad?
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