https://jsfiddle.net/7amfsp10/3/
I added at the begging
<div style="visibility: hidden; position: absolute">
<img style="visibility: hidden; position: absolute" src="http://via.placeholder.com/260x260" aria-hidden="true" alt="">
</div>
That preloads the image that you use in the future. Since browser is smart it won't load the same image twice. So we just load image with the page, then we hide it so it won't be visible, but it's already cashed.
If you want to change the image just change the link inside <img>
and in js code.
#Update
Add attribute aria-hidden="true"
to image to make it invisible for screen readers.
<div style="visibility: hidden; position: absolute">
<img style="visibility: hidden; position: absolute" src="http://via.placeholder.com/260x260" aria-hidden="true" alt="">
</div>
<button id="playButton2" style="display:block; width: 266px; height: 266px; cursor: pointer;background-color: #000000 ;background-image: linear-gradient( to right,transparent 83px,#0059dd 83px, #0059dd 86px, transparent 86px, transparent 174px, #0059dd 174px, #0059dd 177px, transparent 177px ); border: 3px solid #0059dd;"
onclick="
var button = document.getElementById('playButton2');
var player = document.getElementById('player2');
document.querySelector('#playButton2 .initial').style.display='none';
document.querySelector('#playButton2 .pause').style.display='none';
document.querySelector('#playButton2 .play').style.display='none';
player.volume=1.0; if (player.paused) {
playButton2.style.border='3px solid #e77d19';
playButton2.style.background = 'linear-gradient( to right,transparent 83px,#e77d19 83px, #e77d19 86px, transparent 86px, transparent 174px, #e77d19 174px, #e77d19 177px, transparent 177px ), url(\'http://via.placeholder.com/260x260\')';
playButton2.style.backgroundColor = 'transparent';
playButton2.style.backgroundRepeat = 'no-repeat';
playButton2.style.backgroundPosition = 'center';
document.querySelector('#playButton2 .pause').style.display='inline-block';
player.play();
} else {
playButton2.style.border='3px solid #e77d19';
playButton2.style.background = 'linear-gradient( to right,transparent 83px,#e77d19 83px, #e77d19 86px, transparent 86px, transparent 174px, #e77d19 174px, #e77d19 177px, transparent 177px ), url(\'http://via.placeholder.com/260x260\')';
playButton2.style.backgroundColor = 'transparent';
playButton2.style.backgroundRepeat = 'no-repeat';
playButton2.style.backgroundPosition = 'center';
document.querySelector('#playButton2 .play').style.display='inline-block';
player.pause();
}">
<svg class="play" style="display: none;" width="60" height="72" viewbox="0 0 16 14">
<path d="M12.945.38l-.652.7623zM0 4v6h2.804L8 13V1L2.804 4H0zm7-1.268v8.536L3.072 9H1V5h2.072L7 2.732z" fill="#1ed760 " fill-rule="evenodd"></path>
</svg>
<svg class="pause" style="display: none;" width="60" height="72" viewbox="0 0 16 14">
<path d="M12.945.38l-.652.762c1.577 1.462 2.57 3.544 2.57 5.858 0 2.314-.994 4.396-2.57 5.858l.65.763c1.79-1.644 2.92-3.997 2.92-6.62S14.735 2.024 12.945.38zm-2.272 2.66l-.65.762c.826.815 1.34 1.947 1.34 3.198 0 1.25-.515 2.382-1.342 3.2l.652.762c1.04-1 1.69-2.404 1.69-3.96 0-1.558-.65-2.963-1.69-3.963zM0 4v6h2.804L8 13V1L2.804 4H0zm7-1.268v8.536L3.072 9H1V5h2.072L7 2.732z"
fill="#1ed760 " fill-rule="evenodd"></path>
</svg>
<svg class="initial" width="90" height="108" viewbox="0 -10 85 120">
<path fill="currentColor" style="stroke: #e77d19; stroke-width:3px;color:black; " d="M81 44.6c5 3 5 7.8 0 10.8L9 98.7c-5 3-9 .7-9-5V6.3c0-5.7 4-8 9-5l72 43.3z"></path>
</svg>
</button>
<audio id="player2" style="display:none;">
<source src=';' type='audio/mpeg'></source>
</audio>