Is there an alternative to placing images in the source?

Question

I've been studying this page on the Tesla Motors website, because it has some really remarkably cool and sophisticated JavaScript/CSS effects which I'm trying to understand. Scroll down and you'll see what I'm talking about as you scroll.

However, I'm hitting a fundamental barrier-- none of the images on the page are in the source. They all exist only as divs. Where are all the images coming from?

Answer 1

They're background images.

Example from the CSS:

#charging-title {

    position: relative;
    background: url(images/Charging_Title.jpg) 0 0 no-repeat;
    height: 647px;
    overflow: hidden;
    width: 960px;
    margin: 0 auto;

}