JSFiddle - React, Tailwind, and code Playground

HTML

<p>
  Not Scaled
</p>

<div class="wrap wrap1">
  <img alt='sample' src='http://lorempixel.com/500/500/animals/' />

</div>


<p>
  Scaled in HTML
</p>
<div class="wrap wrap2">
  <img alt='sample' class='img2' src='http://lorempixel.com/500/500/animals/' width='150' height='150' />

</div>

<p>
  Scaled in CSS
</p>
<div class="wrap wrap3">
  <img alt='sample' class='img3' src='http://lorempixel.com/500/500/animals/' />

</div>

<p>
  background-size
</p>
<div class="wrap wrap4">

</div>

CSS

body {
  font-family: sans-serif;
  font-size: 14px;
}

.wrap {
  width: 150px;
  height: 150px;
  border: 1px solid #ccc;
  margin: 10px;
}

.img3 {
  width: 100%;
  height: 100%;
}

.wrap1 {
  overflow: scroll;
}

.wrap4 {
  background-color: #fff;
  background-image: url('http://lorempixel.com/500/500/animals/');
  background-size: contain;
  background-repeat: none;
}