How to render youtube field?
$display should be one of view modes (full, teaser, rss or ...) or display setting array:

$display = array(
    'label' =&gt; 'hidden',
    'type' =&gt; 'file_rendered',
    'settings' =&gt; array(
        'file_view_mode' =&gt; 'media_original',
    ),
);