JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
  <div class="inner">
    <img class="real_image" src="http://i.stack.imgur.com/2OrtT.jpg" alt="image"/>
    <img class="placeholder_image"  src="http://i.stack.imgur.com/2OrtT.jpg" alt="image"/>
  </div>
</div>

CSS

.outer{
  width:150px; 
  height:100px; 
  margin: 200px auto; /* just for example */
  border: 1px solid red; /* just for example */
  /* overflow: hidden;	*/ /* TURN THIS ON */
  position: relative;
}
.inner { 
    border: 1px solid green; /* just for example */
    position: absolute;
    top: 50%;
    bottom: 0;
    margin: auto;
    display: table;
    left: 50%;
}
.inner .real_image {
    display: block;
    border: 1px solid blue; /* just for example */
    position: absolute;
    bottom: 50%;
    right: 50%;
    opacity: .5; /* just for example */
}

.inner .placeholder_image{
  opacity: 0.1; /* should be 0 */
}