JSFiddle - React, Tailwind, and code Playground

HTML

<div class="portfolioImage" style="background-image: url('http://placekitten.com/200/150');">
		<div class="footerBar">A Sample Image</div>
	</div>

CSS

.portfolioImage {
       width: 200px;
       height: 150px;
       position: relative;
	   -webkit-transition: all 0.3s ease;
	   -moz-transition:    all 0.3s ease;
       -o-transition:      all 0.3s ease;
       ms-transition:     all 0.3s ease;
       transition:         all 0.3s ease; 
	   opacity: 1.0;
	   z-index: 3;
    }

    .footerBar {    
	   position: relative;
	   top: 50%;
	   transform: translateY(-50%);
       display: none;
       text-align:center;
	   color:#000;
    }

JavaScript

$('.portfolioImage').hover(function(){				        
			$(this).css({"opacity":"0.7"});
			$('.footerBar').css('display','block');
			}, 
			function () {
				$(this).css({"opacity":"1.0"});
				$('.footerBar').css('display','none');
			}
		);