If you click the panel icons on the top-right of a GNOME-3 desktop, you get these panel menus which contain more than just clickable buttons, but widgets like toggle widgets and slider widgets (see the accessibility menu and the sound menu). If you open the accessibility menu and toggle a setting, the menu immediately closes, giving only the briefest indication that a change was made, and not permitting you to undo the change or apply other changes. In contrast, if you open the sound menu and alter the volume setting, you see the change and have an opportunity to fine tune it or continue on to the sound settings window, because the menu does not close.

I'd much prefer it personally if in both cases, altering the state of a configuration option did not close the menu. It is easy enough to navigate away from a menu once you're done editing, and widgets of these kinds are very different from normal menu buttons, so they don't have to close-on-click.

Sorry if this is unclear in any way! I can provide screenshots if necessary.