Comments on [HTML] WINDOWED MODE All Comments

in one of the live examples, it all has a picture behind it. How did you go about adding that?

I'm sososo sorry about the late response to this!! I've been gone for a while it seems!!
If you're referring to this live preview   

The code is

<div style="background-image: url('IMAGEHERE');">

You would place this above the following code
<div class="container" style="width: 100%;">

so, for example, it would look like this!

<div style="background-image: url('https://media.giphy.com/media/3o7bu2drvXlavjcr2E/giphy.gif');">
<div class="container" style="width: 100%;">

Again I'm so sorry I'm late to respond!! I hope this helps!!