如何让Angular/HTML在两个ng-repeat循环之间等待1秒？

<div ng-repeat="item1 in items1">
  <!-- ng-repeat循环1的内容 -->
</div>

<div ng-if="showPlaceholder"></div>

<div ng-repeat="item2 in items2">
  <!-- ng-repeat循环2的内容 -->
</div>

angular.module('myApp', [])
  .controller('myController', function($scope, $timeout) {
    $scope.items1 = [/* 数据源1 */];
    $scope.items2 = [/* 数据源2 */];
    $scope.showPlaceholder = false;

    $timeout(function() {
      $scope.showPlaceholder = true;
    }, 1000);
  });