You have selected to show a window in fullscreen mode. If the application itself does not have an option to turn the fullscreen mode off you will not be able to disable it again using the mouse: use the window operations menu instead, activated using the %1 keyboard shortcut.
Jo ha opdracht jûn om in finster skermfoljend wer te jaan. As de tapassing sels gjin mooglik biedt om dizze modus te ferlitten, dan sille jo sels it finstermenu fan de finstermanager brûke moatte om dizze modus wer te ferlitten. Jo kinne it finstermenu wol oproppe mei de fluchtoets% 1.