That was timeline 4. The one right before the series proper.
Timeline 1 she was kept from being made a magical girl.

Not exactly, in timeline 1 after mami died, she fought alone against walpurgis and won. The image is not timeline 4 because homura has her glasses on, she took of her glasses after timeline 3. This has to be an alternate time line between 2 and 3 (Homura is a magical girl so its no timeline 1, Madoka is not turning into a witch so is not 2 and this doesn't look like timeline 3, as IMO Madoka is about to kick Walpurgis ass in one shot, and thats not timeline 3)