svg icon does not display - rendered size is zero

I think the problem occurs because for me on a desktop the content type description on /node/add only allows about 24 characters per line so if your content type description contains a word or link over 24 characters then it seems that the type tray icon gets squeezed out and rendered as zero pixels.

Good sleuthing! This sounds like a bug to me.

Just looking at this again - for some browser widths, my .png icon does not render, and the browser inspector says for the .png icon "rendered size 0 x 0px".

I can fix this in inspector by adding a width to .type-tray__icon

<div class="type-tray__icon">
          <img width="36" height="36" alt="Icon of a Article content type." src="/sites/default/files/images/icons/newspaper.png">
      </div>