JSFiddle - React, Tailwind, and code Playground

HTML

<div id="thumbsContainer">
	<div class="imageHolder">
        <img src="http://www.gravatar.com/avatar/1a6adef2df4eadd5f83e406eff82c964?s=50&d=identicon&r=PG" />
	</div>
    <div class="imageHolder">
		 <img src="http://www.gravatar.com/avatar/1a6adef2df4eadd5f83e406eff82c964?s=50&d=identicon&r=PG" />
	</div>
    <div class="imageHolder">
		 <img src="http://www.gravatar.com/avatar/1a6adef2df4eadd5f83e406eff82c964?s=50&d=identicon&r=PG" />
	</div>
</div>

CSS

#thumbsContainer {
    background:#900 url('http://www.dvd-ppt-slideshow.com/blog/wp-content/uploads/2009/12/free-christmas-powerpoint-background-red-2.jpg');
    padding:20px;
    overflow:auto;
}

.imageHolder {
    background:#eee;
    float:left;
    margin:5px;
    width:50px;
    height:50px;
    padding:0px;
    border:1px solid #666;
}

JavaScript

$('#thumbsContainer').children('.imageHolder').hover(function() { $(this).siblings().children('img').stop().animate({'opacity':'0.5'}); }, 
	function() { $(this).siblings().children('img').stop().animate({'opacity':'1'}); });