JSFiddle - React, Tailwind, and code Playground

HTML

<div class="thumbnails">
    <div class="thumbnail-wrapper" style='background-image:url(https://1.bp.blogspot.com/-B9t8DAZIFVk/WvPkHSy19FI/AAAAAAAANt4/9t_xTt5JuDMjafGwCwdsb5W3W6BVgTLMgCLcBGAs/s640/Are-You-Human-Too-Poster1.jpg);'></div>
    <div class="thumbnail-wrapper" style='background-image:url(http://intelligen.info/images/Commercial%3ACommissions%3AClients/Poplin/-3.jpeg);'></div>
    <div class="thumbnail-wrapper" style='background-image:url(http://intelligen.info/images/Commercial%3ACommissions%3AClients/Poplin/-4.jpeg);'></div>
    <div class="thumbnail-wrapper" style='background-image:url(http://intelligen.info/images/Commercial%3ACommissions%3AClients/yoga/Screen Shot 2014-05-01 at 10.08.10.png);'></div>
</div>

CSS

body {
    background-color: gray;
}
.thumbnail-wrapper {
    height: 250px;
    margin: 7px;
    width: 250px;
    background-size:cover;
    background-position:center center;
}