These (relative to the AppImage directory) are "papyrus":
./kleopatra.svg ./usr/share/icons/breeze/apps/48/kleopatra.svg ./usr/share/icons/breeze-dark/apps/48/kleopatra.svg
These are "the head":
./usr/share/icons/hicolor/128x128/apps/kleopatra.png ./usr/share/icons/hicolor/16x16/apps/kleopatra.png ./usr/share/icons/hicolor/22x22/apps/kleopatra.png ./usr/share/icons/hicolor/256x256/apps/kleopatra.png ./usr/share/icons/hicolor/32x32/apps/kleopatra.png ./usr/share/icons/hicolor/48x48/apps/kleopatra.png ./usr/share/icons/hicolor/64x64/apps/kleopatra.png
Thus, depending on their icon theme, users will see a different icon, even for VS-NfD.