Seen from a bird's-eye view, the whole tower is visible — its spire, the ring of arched gallery openings around it, and, a little lower, a round window in the tower wall.
For a long time, this round window was just that — a sealed oculus letting light in but leading nowhere. During the tower's restoration, it was turned into a door: now you can step straight out through it onto the narrow balcony that rings the top of the tower, and look out over the palace and park from above — a view once reserved for the birds.
The animation gently brings this photograph to life with motion, leaving its authentic tones unchanged.