JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
    <div class="red"></div>
    <div class="orange"></div>
</div>

CSS

.wrap {
    width: 250px;
    height: 250px;
    position: relative;
    cursor: pointer;
}

.wrap:hover .orange {
    opacity: 1;
}

.wrap div {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
}

.red {
    background-image: url('http://designyoutrust.com/wp-content/uploads/2013/02/AleksandrMavrin04-650x433.jpg');
    background-size: cover;
}

.orange {
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 0 250px 250px;
    border-color: transparent transparent orange transparent;
    opacity: 0;
    z-index: 2;
}