/usr/share/ is in shiki-illustrious-theme 4.6-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/backgrounds/
/usr/share/backgrounds/Arc-Illustrious.png
/usr/share/doc/
/usr/share/doc/shiki-illustrious-theme/
/usr/share/doc/shiki-illustrious-theme/copyright
/usr/share/gnome-background-properties/
/usr/share/gnome-background-properties/arc-illustrious.xml
/usr/share/themes/
/usr/share/themes/Shiki-Illustrious/
/usr/share/themes/Shiki-Illustrious/gtk-2.0/
/usr/share/themes/Shiki-Illustrious/gtk-2.0/Panels/
/usr/share/themes/Shiki-Illustrious/gtk-2.0/Panels/panel-bg-dark.png
/usr/share/themes/Shiki-Illustrious/gtk-2.0/gtkrc
/usr/share/themes/Shiki-Illustrious/gtk-2.0/panel.rc
/usr/share/themes/Shiki-Illustrious/index.theme
/usr/share/doc/shiki-illustrious-theme/changelog.Debian.gz