Aide pour comprendre ce code

Salut,
J'ai besoin de l'aide d'un expert en Symfony pour répondre à une question:

Sur le symfony-demo, dont voici le lien github: Lien Symfony-demo

Dans la méthode newAction, et editAction du controller Admin/BlogController, il y a un return 'post' => $post.

Je me pose donc la question: A quoi cela sert? car dans les vues en question, on ne s'en sert pas (a part si j'ai fais l'impasse sur ca...)

Si quelqu'un pouvait m'aider à comprendre, cela serait cool.

Merci

Extrait code Admin/BlogController:

/**
     * Creates a new Post entity.
     *
     * @Route("/new", name="admin_post_new")
     * @Method({"GET", "POST"})
     *
     * NOTE: the Method annotation is optional, but it's a recommended practice
     * to constraint the HTTP methods each controller responds to (by default
     * it responds to all methods).
     */
    public function newAction(Request $request)
    {
        $post = new Post();
        $post->setAuthorEmail($this->getUser()->getEmail());
        $form = $this->createForm(new PostType(), $post);
        $form->handleRequest($request);
        // the isSubmitted() method is completely optional because the other
        // isValid() method already checks whether the form is submitted.
        // However, we explicitly add it to improve code readability.
        // See http://symfony.com/doc/current/best_practices/forms.html#handling-form-submits
        if ($form->isSubmitted() && $form->isValid()) {
            $post->setSlug($this->get('slugger')->slugify($post->getTitle()));
            $em = $this->getDoctrine()->getManager();
            $em->persist($post);
            $em->flush();
            return $this->redirectToRoute('admin_post_index');
        }
        return $this->render('admin/blog/new.html.twig', array(
            'post' => $post,
            'form' => $form->createView(),
        ));
    }
    /**
     * Finds and displays a Post entity.
     *
     * @Route("/{id}", requirements={"id" = "\d+"}, name="admin_post_show")
     * @Method("GET")
     * @Security("post.isAuthor(user)")
     *
     * NOTE: You can also centralize security logic by using a "voter"
     * See http://symfony.com/doc/current/cookbook/security/voters_data_permission.html
     */
    public function showAction(Post $post)
    {
        $deleteForm = $this->createDeleteForm($post);
        return $this->render('admin/blog/show.html.twig', array(
            'post'        => $post,
            'delete_form' => $deleteForm->createView(),
        ));
    }