Index: src/wp-admin/css/colors/_admin.scss
===================================================================
--- src/wp-admin/css/colors/_admin.scss	(revision 29609)
+++ src/wp-admin/css/colors/_admin.scss	(working copy)
@@ -413,8 +413,10 @@
 	background-color: $highlight-color;
 }
 
-.details.attachment {
-	box-shadow: 0 0 0 1px #fff, 0 0 0 5px $highlight-color;
+.details.attachment,
+.selected.attachment:focus {
+	box-shadow: inset 0 0 0 3px #fff,
+	            inset 0 0 0 7px $highlight-color;
 }
 
 .attachment.details .check {