KDE Plasma did something (or is a bug) to show the symbolic icon of user-desktop regardless if is Show Desktop Widget or Minimize All widget when are shown on desktop or panel.
If you go to /usr/share/plasma/plasmoids and look inside org.kde.plasma.minimizeall or org.kde.plasma.showdesktop folders, you will see that the metadata.desktop files both show the colored version of icons, as those shown when you drag the widget - is defined in that file, that point as mentioned to user-desktop and should scale, but it doesn’t no matter what icons theme you use.
1 Like