Tracks
For the first time, she noticed them.
Tracks in the dirt, going every which way that was possible for her little garbage bot.
She wondered how many were his. How long had he been so alone? How many of the tracks of his brothers had been completely eroded away? Were his the only ones left? Could all these track marks be from the WALL-E she knew, roaming by himself? Wasn't he ever tired of it? Didn't he ever complain? How could he keep those tracks so fresh, despite everything?
Or maybe that was what she loved about him.