JSFiddle - React, Tailwind, and code Playground

HTML

<div id="immagine1">
    <p>There's some text in this div!</p>
    <img src="http://www.ctd.northwestern.edu/images/youtube-logo(2).jpg" alt="logo_key_css" width="169" height="53"/>
</div>

CSS

#immagine1 { height: 300px; width: 300px; border: solid 1px black; }

JavaScript

$(function() {
    $('div img').hide();
    $('#immagine1').hide().fadeIn(5000, function() {
        $('div').mouseenter(function() {
            $(this).find('img').fadeIn('1000');
        });
    });
});