JSFiddle - React, Tailwind, and code Playground

HTML

<div id="img1"></div>

<img id="pic1" src="http://i.imgur.com/uKnMvyp.jpg" class="hide" alt="wolf">
<img id="pic2" src="http://i.imgur.com/TOUfCfL.jpg" class="hide" alt="cat">

CSS

#img1 {
    width: 480px; 
    height: 320px; 
    background: -moz-element(#pic2) no-repeat;
    background-size: 100% 100%;
}

.hide {display: none}