JSFiddle - React, Tailwind, and code Playground

HTML

<div id="thumbs">
    <img src="http://upload.wikimedia.org/wikipedia/en/6/6a/Chaplin-charlie.jpg" />
    <img src="http://upload.wikimedia.org/wikipedia/en/6/6a/Chaplin-charlie.jpg" />
    <img src="http://upload.wikimedia.org/wikipedia/en/6/6a/Chaplin-charlie.jpg" />
    <img src="http://upload.wikimedia.org/wikipedia/en/6/6a/Chaplin-charlie.jpg" />
    <img src="http://upload.wikimedia.org/wikipedia/en/6/6a/Chaplin-charlie.jpg" />
</div>

CSS

*            {padding:0; margin:0;}

#thumbs      {oveflow:hidden;}
#thumbs img  {float:left; display:inline; width:100px; margin:10px; cursor:pointer; opacity:0.3;}

JavaScript

$(document).ready(function(){
    // Attach listeners to the thumbs.
    $('#thumbs img').hover(function(){
        $(this).animate({opacity: 1.0});
    }, function(){
        $(this).animate({opacity: 0.3});
    });
});