Okay, so in the latest version there's this new feature:
A new atom var, override, can be applied to images to make them appear in place of the atom's normal icon and overlays. This can be used to give a custom appearance for any atom to only certain players.
From this page: http://www.byond.com/docs/notes/482.html
But, that's either poorly worded or just wrong.
The way the override var actually works, is essentially as a boolean, when true, it replaces (as mentioned) the icon of the image's loc var. (So, you still have to set the image's loc for it to work, and it uses that loc as the atom it replaces.)
I didn't post this as a bug report, because it doesn't seem like a bug, per se.
Just thought I should point this out.
I don't know if Lummox JR will see this post anytime soon, though.