Cleaned unnecessary stuff

Resources/doc/cookbook/recipe_dynamic_form_modification.rst

@@ -23,10 +23,8 @@ In your ``Admin`` class's ``configureFormFields`` method you're able to get the
 
         $subject = $this->getSubject();
 
-        // $subject is your underlying model,
-        // do what you need to figure out if you'll have to modify the form
         if ($subject->isNew()) {
-            // The thumbnail field will only be added when the edited item is newly created
+            // The thumbnail field will only be added when the edited item is created
             $formMapper->add('thumbnail', 'file');
         }
       }