diff -r 346c88efed21 -r 5e2f62d02dcd wp/wp-content/themes/twentyfifteen/js/keyboard-image-navigation.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-content/themes/twentyfifteen/js/keyboard-image-navigation.js	Tue Jun 09 03:35:32 2015 +0200
@@ -0,0 +1,22 @@
+/**
+ * Twenty Fifteen keyboard support for image navigation.
+ */
+
+( function( $ ) {
+	$( document ).on( 'keydown.twentyfifteen', function( e ) {
+		var url = false;
+
+		// Left arrow key code.
+		if ( e.which === 37 ) {
+			url = $( '.nav-previous a' ).attr( 'href' );
+
+		// Right arrow key code.
+		} else if ( e.which === 39 ) {
+			url = $( '.nav-next a' ).attr( 'href' );
+		}
+
+		if ( url && ( ! $( 'textarea, input' ).is( ':focus' ) ) ) {
+			window.location = url;
+		}
+	} );
+} )( jQuery );