<!doctype html>
<html>
<head>
  <meta charset='utf-8'>
<style>
  .content + .content > .item > .copy-this {
  color: yellow;
  background: black;
}
.random-div {
  color: brown;
}
.ruler {
  position:fixed;
  bottom:20px;
  left:0;
  width: 600px;
  background:blue;
  height:5px;
  border: 1px dashed gold;
}
</style>
</head>
<body>
  <div class="content">
    <div class="item">
      <div class="copy-this">Some info 1[#1]</div>
      <div class="random-div">Not to copy 1[#1]</div>
    </div>
    <div class="item">
      <div class="copy-this">Some info 2[#1]</div>
    </div>
    <div class="item">
      <div class="copy-this">Some info 3[#1]</div>
      <div class="random-div">Not to copy 2[#1]</div>
    </div>
    <div class="item">
      <div class="copy-this">Some info 4[#1]</div>
    </div>
  </div>
  <div class="content">
    <div class="item">
    </div>
    <div class="item">
      <div class="random-div">This is original content[#2]</div>
    </div>
    <div class="item">
    </div>
    <div class="item">
    </div>
  </div>
  <hr class='ruler'>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

  <script>
/* Create a MediaQueryList with matchMedia() method.
|  Add a MediaQueryListener and handler.
|  Invoke handler and pass MediaQueryList.
*/
var mql = window.matchMedia("(min-width: 600px)");
mql.addListener(viewportObserver);
viewportObserver(mql);

/* Given a MediaQueryList...
|  ...use the .matches property to...
|  ...determine the viewport size...
|  ...If viewport is 600px or more...
|  ...remove all cloned content...
|  ...otherwise, clone content...
|  ...and add it to the destination.
*/
function viewportObserver(MediaQueryList) {
  var target = $('.content + .content > .item').eq(idx);
  if(MediaQueryList.matches) {
    target.each(function(idx, obj) {
      $(this).remove('.copy-this');
    });
  }
  else {
    $('.copy-this').each(function(idx, obj) {
      var clone = $(this).clone(true, true);
      target.prepend(clone);
    });
  }
}

/* If for whatever reason the mediaQueryListener...
|  ...is no longer needed, use...
*/// mql.removeListener(viewportObserver);
  </script>
</body>
</html>


// Code goes here

/* Styles go here */