Index: src/wp-includes/media.php
===================================================================
--- src/wp-includes/media.php	(revision 34361)
+++ src/wp-includes/media.php	(working copy)
@@ -148,7 +148,8 @@
  * @param int          $id   Attachment ID for image.
  * @param array|string $size Optional. Image size to scale to. Accepts a registered image size
  *                           or flat array of height and width values. Default 'medium'.
- * @return false|array False on failure, array on success.
+ * @return false|array Array containing the image URL, width, height, and boolean for whether
+ *                     the image is an intermediate size. False on failure.
  */
 function image_downsize( $id, $size = 'medium' ) {