JSFiddle - React, Tailwind, and code Playground

HTML

<aside id="banner">
    <img src="http://htmlforum.ru/public/style_images/master/profile/default_large.png" />
</aside>

CSS

#banner {
    height: 150px;
    margin-top: 15px;
    background-color: rgb(150,150,150);
    overflow: hidden;
}

JavaScript

var img = document.images[0];
var banner = document.getElementById('banner');

img.style.width = banner.clientWidth + "px";
img.style.height = banner.clientHeight + "px";