Hello There was a patch in June 2020 that added bubblewrap as input to gnome- dektop. It was reported that the patch was enabling thumbnails in Nautilus. So, this issue should had been resolved. https://issues.guix.gnu.org/41756
But thumbnails are still not generated for me with Nautilus (GNOME Files) version 41.1, gnome-desktop 40.4. Roman