determining, by a computer system, that a window for an application running on the computer system has become locked by the application while the window is minimized;

in response to determining that the window has become locked while minimized, changing, by the computer system, a preview image associated with the application to an icon or to a different image;

after the changing, determining, by the computer system, that the window has been restored or maximized; and

in response to determining that the window has been restored or maximized, causing, by the computer system, the preview image to reflect a current visual state of the window.