The shadow of a picture is the picture recoloured to the shadow colour,
but drawing the picture left its pixel-space transform set, so the
recolouring rectangle (sized in points) covered only part of a picture
whose bitmap is bigger than it is shown: a 400 px photo at 240 pt cast a
shadow of its top-left corner only. The shape's transform is restored
before recolouring.
Wild synthetic set: framed pictures with shadows 7.67 -> 5.95, rotated
picture with a shadow 10.67 -> 10.07.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>