shouldn't imagefield_widget_settings_form() be using a more specific theme function?

The preview of the default image in the widget settings is made thus:

  if (!empty($widget['default_image'])) {
    $form['default']['default_image_thumbnail'] = array(
      '#type' => 'markup',
      '#value' => theme('imagefield_image', $widget['default_image'], '', '', array('width' => '150'), FALSE),
    );
  }

Would one of these theme functions not be better suited to this?

    // Use to generate a preview (admin view) of an imagefield item for use in
    // field item forms and filefield widgets. Invoked by filefield_widget_process.
    'imagefield_widget_preview' => array(
      'arguments' => array('item' => NULL),
    ),
    // Theme function for the field item elements. allows you to place children
    // within the context of the parent.
    'imagefield_widget_item' => array(
      'arguments' => array('element' => NULL),
    ),
    // Generates and img tag to the admin thumbnail of an ImageField upload.
    'imagefield_admin_thumbnail' => array(
      'arguments' => array('item' => NULL),
    ),