nachladen von Grafiken welche außerhalb des sichtbaren Bereichs sind.

https://t3n.de/news/jquery-unveil-wahrscheinlich-475653/

JTL Forum:
https://forum.jtl-software.de/threads/wie-kann-ich-bilder-im-content-den-lazy-load-effekt-zuweisen.122966/#post-671571

http://jquery.eisbehr.de/lazy/example_show-a-loading-image

<img class="lazy" data-src="images/1.jpg" />
<img class="lazy" data-src="images/2.jpg" />
<img class="lazy" data-src="images/3.jpg" />
<img class="lazy" data-src="images/4.jpg" />
<img class="lazy" data-src="images/5.jpg" />
<img class="lazy" data-src="images/6.jpg" />

// plugin build-in placeholder management
$(function() {
  $('.lazy').lazy({
     placeholder: "data:image/gif;base64,R0lGODlhEALAPQAPzl5uLr9Nrl8e7..."
  });
});

img.lazy {
        width: 700px; 
        height: 467px; 
        display: block;
 
        /* optional way, set loading as background */
        background-image: url('images/loading.gif');
        background-repeat: no-repeat;
        background-position: 50% 50%;
    }