code: function showDevice(device, isShowing) {
    $('#device-' + device).checked = isShowing;
  
    var rendered = $('#' + device);
    if(!rendered) {
      var template = $('#' + device + '-frame-template');
      var clone = document.importNode(template, true);
      $('preview').appendChild(clone.content);
      //check for extra params in location.url to pass on to iframes
      var params = document.location.href.split('?');
      if (params) {
        var newparams = params[params.length - 1];
        var oldsrc = $('preview .frame').getAttribute('src');
        $('preview .frame').setAttribute('src', oldsrc + '&' + newparams);
      }
    } else {
      rendered.style.display = isShowing ? '' : 'none';
    }
  }
docs: Show one of the devices