I guess so, you could use wget to grab an image from the web first, then display it...

I'm using hsetroot to display the image on the root X window. You might be able to find another tool that puts web pages there. Look around the Debian repos for something...

Heck, you could have hang gliders flying around, or fireworks, or the phase of the moon, or Scottish tartans. Feel free to experiment, I recommend Easy Debian to find stuff that works.