Исправление Vsevolod-linuxoid, (текущая версия) :
https://forum.xfce.org/viewtopic.php?id=9441
The setting is located on the Compositor tab. Settings Manager >> Window Manager Tweaks >> Compositor >> «Show windows preview in place of icons when cycling».
Запустил в виртуалке Xubuntu 18.04
Исходная версия Vsevolod-linuxoid, :
The setting is located on the Compositor tab. Settings Manager >> Window Manager Tweaks >> Compositor >> «Show windows preview in place of icons when cycling».