JSFiddle - React, Tailwind, and code Playground

HTML

<div class="twentytwenty-container" data-image-num="1">
    <img src="http://placehold.it/500x300/" />
</div>

<div class="imageSet" data-image-num="1">
    <img src="http://placehold.it/200x100/" />
</div>

CSS

.twentytwenty-container {
    display:none;
}

JavaScript

$('.imageSet').click(function() {
	var imageNum = $(this).attr('data-image-num');
	$('.twentytwenty-container[data-image-num="' + imageNum + '"]').show();
});