A raw's embedded JPEG, a thumbnail, the previous render after an edit or the magnified
frame under a 1:1 window all look like the finished photo. Once a render has been on its
way for 0.5 s with nothing new on screen, a pill at the bottom of the photo (widget
`loupe:rendering`) says so; above the Navigator when that is in the way.
The wait starts when the render starts coming (an idle app draws no frames), so a quick
render never shows it, nor does a drag whose drafts keep up; once up it stays until
nothing is coming, so slow drafts don't make it blink. It watches what is on screen: the
After or the Before, and the windows in use. Not an activity row: it says the pixels
aren't final (docs/background-tasks.md).
Co-Authored-By: Claude <noreply@anthropic.com>
