JSFiddle - React, Tailwind, and code Playground

HTML

<div style='position:relative'>
    <div id='tag' style=' border: 1px solid red; position : absolute; top: 20px; left: 20px; width: 50px; height: 50px;'></div>
    <img src='http://www.hihowareyou.com/store/images/products/tn_HiVinylFrontmed.jpg' id='wow'>
</div>

JavaScript

var tag = document.getElementById('tag');

tag.onmouseover = function () {
    tag.style.opacity = 0;
}
tag.onmouseout = function () {
    tag.style.opacity = 1;
}