Index: src/wp-admin/includes/image.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/wp-admin/includes/image.php	(revision c3615b26889514a0501ee6383f2622d944413dbf)
+++ src/wp-admin/includes/image.php	(date 1519998607000)
@@ -554,7 +554,7 @@
  * @return bool True if suitable, false if not suitable.
  */
 function file_is_displayable_image( $path ) {
-	$displayable_image_types = array( IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_BMP );
+	$displayable_image_types = array( IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_BMP, IMAGETYPE_ICO );
 
 	$info = @getimagesize( $path );
 	if ( empty( $info ) ) {