JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://raw.githubusercontent.com/scottjehl/picturefill/master/src/picturefill.js"></script>
<img src="http://placehold.it/300x150" srcset="http://placehold.it/300x150, http://placehold.it/600x300 2x" alt="Alternative" />

CSS

img { height: 150px; width: 300px; }

JavaScript

$(document).bind('ready page:load', function() {
  window.picturefill()
});