Visible crew/equipment: When Satine is singing 'One day I'll fly away,' she goes up the steps to the top of the elephant. If you look to the top windows of the building behind her, you can see a strange shape gliding past the lit windows from left to right. I'm not sure what it is, since it isn't the shape of a person and it looks like it's on a track. Then when Satine sings, 'Why live life from dream to dream?' the shape goes back from right to left, and at the last second, before it cuts to Christian, the lights go out. Now, I've seen the behind-the-scenes of footage of Moulin Rouge, and that scene was probably behind a blue screen so I haven't a clue what the shape is.