akr_dsk_preview.js

(function() {
  var d = document;
  var img = d.createElement('img');
  img.style.cssText = 'right:0; top:0; position:fixed;';
  d.body.appendChild(img);

  var elems = d.querySelectorAll('a[href^="./"]');

  Array.prototype.forEach.call(elems, function(elem) {
    elem.addEventListener('mouseover', function() {
      if (elem.href) { img.src = elem.href; } // ???
    })
  });
}());