JSFiddle - React, Tailwind, and code Playground

HTML

<div id='images-wrapper'>
    <ul>
        <li>
            <img class='small' src='http://placehold.it/50/ff0000'/>
            <img class='big' src='http://placehold.it/300/ff0000'/>
        </li>
        <li>
            <img class='small' src='http://placehold.it/50/ff9900'/>
            <img class='big' src='http://placehold.it/300/ff9900'/>
        </li>
        <li>
            <img class='small' src='http://placehold.it/50/ff0099'/>
            <img class='big' src='http://placehold.it/300/ff0099'/>
        </li>
        <li>
            <img class='small' src='http://placehold.it/50/00ff00'/>
            <img class='big' src='http://placehold.it/300/00ff00'/>
        </li>
        <li>
            <img class='small' src='http://placehold.it/50/0000ff'/>
            <img class='big' src='http://placehold.it/300/0000ff'/>
        </li>
        <li>
            <img class='small' src='http://placehold.it/50/0099ff'/>
            <img class='big' src='http://placehold.it/300/0099ff'/>
        </li>
    </ul>
    <div class='preview-area'></div>
</div>

CSS

#images-wrapper {
    position: relative; /* required ! */
    min-height: 400px;
    min-width: 530px;
    /* just to make things visible */
    outline: 1px solid red;
    margin: 5px;
}

ul {
    width: 150px;
    float: left;
}

.big {
    display: block;
    position: absolute;
    top: 54px;
    right: 54px;
    opacity: 0;
    transition: opacity .5s;
}

li {
    display: inline-block;
    margin: 10px;
}

.preview-area {
    width: 350px;
    height: 350px;
    border: 4px solid blue;
    position: absolute;
    top: 21px;
    right: 21px;
}
li:hover .big {
    opacity: 1;
}