SUMMARY Even after a custom background is applied to an SDDM theme, the thumbnail retains the default image. It would be convenient to see the currently chosen background, if that's been changed. STEPS TO REPRODUCE 1. In System Settings -> Login Screen (SDDM) click the Background icon for Breeze or any theme 2. Select a new backgound image 3. Click Apply and authenticate OBSERVED RESULT The thumbnail for the theme's default image is shown EXPECTED RESULT The thumbnail for the chosen theme is shown SOFTWARE/OS VERSIONS Operating System: Solus 4.7 KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.2 Kernel Version: 6.15.6-321.current (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION This is also the case on git-master IIRC this is intentional / the expected behavior right now
This isn't feasible to do unfortunately. The preview is an image supplied by the vendor of the theme.