Needed a quotation mark on both sides of the "500".
Code as you entered except FR software cleans off the <*/img> to save space:
<*img src="https://pbs.twimg.com/media/D0E0QoYWoAAwDaO.jpg"WIDTH=500" />
Code it like this less the asterisk instead:
<*img src="https://pbs.twimg.com/media/D0E0QoYWoAAwDaO.jpg"WIDTH="500" />
Remove asterisk gives you this:
