ao2.it
Antonio Ospite, theorist attacks

it looks like menus are bound to pointers and not to windows, is this really the expected behavior?

Debatable, I guess. For menus opened from a menu bar, probably not - it's too confusing for them to become detached from the menubar, as that video clip shows. On the other hand, it might make sense for context menus. Of course, it might not make sense either for one pointer to be able to move the menu away from the other pointer which opened it. Debatable...