You know how you can place two objects on the same tile if you use the move_objects on cheat? Well I only know how to do that on the floor - if I try to put two objects on the same surface tile (for example a desk), one item will go on top of the desk and the other will sit on the floor in the same tile.

My question is, how do I get two items to overlap on a surface tile? I've seen this done in screenshots so I know it's possible. Here's a screenshot of what I mean (not my screenshot):





You see how the Oreo box and microwave can sit on the same counter tile? Yeah, that's what I want to know how to do. Thanks in advance.

By using invisible slot items such as these:
http://www.modthesims2.com/showthread.php?t=178963
http://www.modthesims2.com/showthread.php?t=178902
http://www.modthesims2.com/showthread.php?t=178791