JSFiddle - React, Tailwind, and code Playground

HTML

<div class="row1"><img class="a" src="http://imgur.com/Y7Cz2Q3.jpg"><img class="c" src="http://imgur.com/HHbpx0w.jpg"></div>
    
<div class="row2"><img class="b" src="http://imgur.com/MMZwSdO.jpg"><img class="d" src="http://imgur.com/Q9LfCwH.jpg"></div>

CSS

img.b {
	opacity:0;
	}
	
	img.a:hover img.b {
	opacity:1;
	}

img.d {
	opacity:0;
	}
	
	img.c:hover img.d {
	opacity:1;
	}