As the screenshot clearly shows, the app to take screenshots and the app to indicate the battery level never got closed.
Yes your are absolutely correct, even it display no of application are closed it actually free resources used by application.As per my understanding it closes some running services which are nothing but UI less applications.Some applications which are installed in device uses this service for many reasons such as alarm clock, or to check periodic update of an applications etc.
There are some service though that even you close them manually they just get restarted.