Index: wp-includes/css/media-views-rtl.css
===================================================================
--- wp-includes/css/media-views-rtl.css	(revision 23024)
+++ wp-includes/css/media-views-rtl.css	(working copy)
@@ -232,6 +232,8 @@
 .media-selection .selection-info a:last-child {
 	border-right: 1px;
 	border-left: 0;
+	margin-left: 0;
+	margin-right: -8px;
 }
 
 .media-selection:after {
Index: wp-includes/css/media-views.css
===================================================================
--- wp-includes/css/media-views.css	(revision 23024)
+++ wp-includes/css/media-views.css	(working copy)
@@ -1133,10 +1133,15 @@
 	vertical-align: top;
 }
 
-.media-selection.empty {
+.media-selection.empty,
+.media-selection.editing {
 	display: none;
 }
 
+.media-selection.one .edit-selection {
+	display: none;
+}
+
 .media-selection .count {
 	display: block;
 	padding-top: 12px;
@@ -1164,6 +1169,7 @@
 
 .media-selection .selection-info a:last-child {
 	border-right: 0;
+	margin-right: 0;
 }
 
 .media-selection .selection-info .clear-selection {
Index: wp-includes/js/media-views.js
===================================================================
--- wp-includes/js/media-views.js	(revision 23024)
+++ wp-includes/js/media-views.js	(working copy)
@@ -1562,7 +1562,7 @@
 					toolbar:    'main-gallery',
 					filterable: 'uploaded',
 					multiple:   'add',
-					editable:   true,
+					editable:   false,
 
 					library:  media.query( _.defaults({
 						type: 'image'
@@ -3609,6 +3609,7 @@
 
 			this.views.set( '.selection-view', this.attachments );
 			this.collection.on( 'add remove reset', this.refresh, this );
+			this.controller.on( 'content:activate', this.refresh, this );
 		},
 
 		ready: function() {
@@ -3620,9 +3621,15 @@
 			if ( ! this.$el.children().length )
 				return;
 
+			var collection = this.collection,
+				editing = 'edit-selection' === this.controller.content.mode();
+
 			// If nothing is selected, display nothing.
-			this.$el.toggleClass( 'empty', ! this.collection.length );
-			this.$('.count').text( this.collection.length + ' ' + l10n.selected );
+			this.$el.toggleClass( 'empty', ! collection.length );
+			this.$el.toggleClass( 'one', 1 === collection.length );
+			this.$el.toggleClass( 'editing', editing );
+
+			this.$('.count').text( collection.length + ' ' + l10n.selected );
 		},
 
 		edit: function( event ) {