I was working on a mod in the Creation Kit and I noticed that it seemed like there were objects appearing in the render window that did not appear in-game.

Here's a screenshot of the render window with the scene in question:
http:// i44.tinypic.com/ 2a8eool.jpg

And here's a screenshot of the area in-game, though with a different camera angle.
http:// i42.tinypic.com/ 2h561k2.jpg

The Khajit Caravan is currently camped there in the second screenshot.

I'm wondering if the stuff is supposed to be missing (maybe I haven't completed the required in-game quest or something), or if something has gone horrendously wrong and I've broken everything?

(I ask because I'm working on modding the caravans a bit and I'm afraid I've broken them.)

You certainly broke the enable parent.

Planteur sounds correct. The caravans all have enable markers because they aren't all always in the same place. It looks like you've broken a connection somewhere or messed with something that controls that part of it, so the people show up but the camp items are gone.