RAINBOW ON MY WALL

It's a lovely clear sunny day today, and this was to the left of my monitor when I sat down, which made it worth coming into the office. Perhaps someone who knows physics (Meles?) can explain why it seems to be double, with the second red showing as pink down the middle, when by the time it moved across the room it was a normal ROYGBIV spectrum, starting with the red to the left.

Pretty when biggified.