Index: src/js/media/views/attachments/browser.js
===================================================================
--- src/js/media/views/attachments/browser.js	(revision 57599)
+++ src/js/media/views/attachments/browser.js	(working copy)
@@ -423,6 +423,7 @@
 
 		if ( ! this.collection.length ) {
 			this.toolbar.get( 'spinner' ).show();
+			this.toolbar.$( '.media-bg-overlay' ).show();
 			this.dfd = this.collection.more().done( function() {
 				if ( ! view.collection.length ) {
 					noItemsView.$el.removeClass( 'hidden' );
@@ -430,10 +431,12 @@
 					noItemsView.$el.addClass( 'hidden' );
 				}
 				view.toolbar.get( 'spinner' ).hide();
+				view.toolbar.$( '.media-bg-overlay' ).hide();
 			} );
 		} else {
 			noItemsView.$el.addClass( 'hidden' );
 			view.toolbar.get( 'spinner' ).hide();
+			this.toolbar.$( '.media-bg-overlay' ).hide();
 		}
 	},
 
Index: src/js/media/views/toolbar.js
===================================================================
--- src/js/media/views/toolbar.js	(revision 57599)
+++ src/js/media/views/toolbar.js	(working copy)
@@ -28,10 +28,12 @@
 		// The toolbar is composed of two `PriorityList` views.
 		this.primary   = new wp.media.view.PriorityList();
 		this.secondary = new wp.media.view.PriorityList();
+		this.tertiary  = new wp.media.view.PriorityList();
 		this.primary.$el.addClass('media-toolbar-primary search-form');
 		this.secondary.$el.addClass('media-toolbar-secondary');
+		this.tertiary.$el.addClass('media-bg-overlay');
 
-		this.views.set([ this.secondary, this.primary ]);
+		this.views.set([ this.secondary, this.primary, this.tertiary ]);
 
 		if ( this.options.items ) {
 			this.set( this.options.items, { silent: true });
@@ -122,6 +124,7 @@
 		delete this._views[ id ];
 		this.primary.unset( id, options );
 		this.secondary.unset( id, options );
+		this.tertiary.unset( id, options );
 
 		if ( ! options || ! options.silent ) {
 			this.refresh();
Index: src/wp-includes/css/media-views.css
===================================================================
--- src/wp-includes/css/media-views.css	(revision 57599)
+++ src/wp-includes/css/media-views.css	(working copy)
@@ -2809,6 +2809,34 @@
 		font-size: 14px;
 		line-height: 2.71428571;
 	}
+
+	.media-frame .wp-filter .media-toolbar-secondary {
+		position: unset;
+	}
+	
+	.media-frame .media-toolbar-secondary .spinner {
+		position: absolute;
+		top: 0;
+		bottom: 0;
+		margin: auto;
+		left: 0;
+		right: 0;
+		z-index: 9;
+	}
+	
+	.media-bg-overlay {
+		content: '';
+		background: #ffffff;
+		width: 100%;
+		height: 100%;
+		display: hidden;
+		position: absolute;
+		left: 0;
+		right: 0;
+		top: 0;
+		bottom: 0;
+		opacity: 0.6;
+	}
 }
 
 /* Responsive on portrait and landscape */