A girl called Mara had a friend, Lucy, who copied her — online especially. Mara would post a certain style of photo, and days later Lucy would post almost the same. Mara made a joke account; Lucy made one just like it. Mara got into something new; Lucy was suddenly into it too, posting as if she'd discovered it. At first Mara found it flattering, then annoying, then a bit unsettling — like her own choices were being absorbed and handed back. When she said something, Lucy got upset and said Mara didn't "own" things and was being big-headed. Maybe Lucy just genuinely liked the same stuff. But it had started to feel like being slowly turned into two of the same person. Mara didn't know whether she was being unfair or whether something real was wrong.