JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box"></div>

CSS

.box {
    width: 50px;
    height: 50px;
    float: left;
    border: 1px solid #000;
    position:absolute;
    top: 100px;
    left: 100px;
}

.box::after{
    content: url(http://www.clker.com/cliparts/9/5/e/b/12428065451316964828Simple_crown_icon.svg.med.png);
    position: absolute;
    top: -10px;
    right: -10px;
    width: 0.1em;
    height: 0.1em;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
}