JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block">
            <div class="popup"></div>
            <div class="image"></div>
</div>

CSS

.block { position: relative; width: 400px; height: 400px; background: #ccc; }
.popup { display: none;
    position: absolute; left: 0; top: 0; width: 200px; height: 200px; background: #eee; z-index: 40; }
.image { position: relative; width: 100px; height: 100px; background: #aaa; z-index: 30;

JavaScript

$(".block .image").mouseover(
                function(){
                        $(this).parent().find(".popup").show();
                }
        );

$(".popup").mouseout(
    function(){
        $(this).hide()
            });