clicktorelease-html-progressive-loading-image.html

<div class="hero image">
    <!-- the lazy loaded image -->
    <!-- thumb-src is a matrix of DCT coefficients -->
    <!-- note that a background-color is also set so -->
    <!-- it is rendered while the image is fetched -->
    <div thumb-lazy
      original-src="/images/graphical-web-2016.jpg"
      thumb-src="/images/graphical-web-2016-thumb.png"
      thumb-width="2880" thumb-height="1800"
      style="background-color:#121513;width:100%">
    <!-- a div with intrinsic ratio -->
    <div style="padding-bottom:62.5%">
        <!-- fallback for browsers not using JS / bots -->
        <noscript><img src="/images/graphical-web-2016.jpg"></noscript>
    </div>
</div>