th="238" data-expected-height="52" data-offset-y="141" data-offset-x="159"
  >
</div>
<!-- Viewbox + css width. Has aspect_ratio and width. Height is scaled -->
<div class="container">
  <img class="target" style="width:238px" src="data:image/svg+xml,%3Csvg viewBox='0 0 100 10' xmlns='http://www.w3.org/2000/svg' %3E%3Crect width='100%' height='100%' style='fill:rgb(0,255,0);'/%3E%3C/svg%3E"
  data-expected-width="276" data-expected-height="56" data-offset-y="137" data-offset-x="121"
  >
</div>
<script>
  //