chromium/third_party/blink/web_tests/compositing/reflections/nested-reflection.html

<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <style>
  .outer {
    width: 120px;
    height: 230px;
    margin: 20px;
    border: 1px solid black;
    -webkit-box-reflect: right 10px;
  }
  
  .inner {
    margin: 10px;
    width: 100px;
    height: 100px;
    background-color: green;
    text-align: center;
    font-size: 50pt;
    -webkit-box-reflect: below 10px;
  }
  
  .composited {
    will-change: transform;
  }

  </style>
  </head>
<body>
<p>You should see the original and three copies of the blue box.</p>
  <div class="outer composited">
    <div class="inner composited">
      1
    </div>
  </div>
</body>
</html>