code: public function mediaAction(Request $request, Application $app)
      {
          $options = array(
              "connector" => $app["red_kite_cms.elfinder_media_connector"],
          );
  
          return parent::show($options);
      }
docs: Show ElFinder for image files action
  
  @param \Symfony\Component\HttpFoundation\Request $request
  @param \Silex\Application                        $app
  @return \Symfony\Component\HttpFoundation\Response