scaleX()

transform: scaleX(1);

transform: scaleX(0.7);

transform: scaleX(1.3);

transform: scaleX(-0.5);

<section id="default-example">
  <img
    class="transition-all"
    id="example-element"
    src="/proxy/developer.mozilla.org/shared-assets/images/examples/firefox-logo.svg"
    width="200" />
</section>

scaleX(s)

<p>foo</p>
<p class="transformed">bar</p>

p {
  width: 50px;
  height: 50px;
  background-color: teal;
}

.transformed {
  transform: scaleX(2);
  background-color: blue;
}

<p>foo</p>
<p class="transformed">bar</p>

p {
  width: 50px;
  height: 50px;
  background-color: teal;
}

.transformed {
  transform: scaleX(2);
  transform-origin: left;
  background-color: blue;
}