From my AU, The Flutterby Effect - although this could certainly just be taken on its own as a picture of grown up Luna : PIn the AU, Princess Celestia is the one corrupted by the Nightmare forces instead of Luna, becoming the terrifying Phantasm Sky and forcing Luna to banish her to the moon. 1000 years of ruling alone has led Luna to grow to her full height, no longer quite the 'little' sister anymore when Celestia is freed by the Elements.(there's probably a glaring error in this i haven't spotted because it's 3 am, but whatever, i'm uploading it anyway)Companion piece: