JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <img src="http://placekitten.com/285/275" class="portfolio" alt="">
    <div class="mask">
         <h2>Froosh</h2>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quidem nostrum     porro iste excepturi vel ducimus cumque minima rem voluptates cum!</p>
    </div>
</div>

CSS

.container {
    /* Some width */
    width: 200px;
    display: inline-block;
    position: relative;
    border: 3px solid #ccc;
}
.container img {
    display: block;
    width: 100%;
}
.container .mask {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    /* some color */
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    -webkit-transition: all 0.3s ease-out;
    /* Chrome 1-25, Safari 3.2+ */
    -moz-transition: all 0.3s ease-out;
    /* Firefox 4-15 */
    -o-transition: all 0.3s ease-out;
    /* Opera 10.50–12.00 */
    transition: all 0.3s ease-out;
    /* Chrome 26, Firefox 16+, IE 10+, Opera 12.10+ */
}
.container:hover .mask {
    opacity: 1;
}