Making a small (parlour-size) box, copying the design in Tarbell.
Tarbell's version means that when the box is tipped over and open, the visible "bottom" is actually in three parts, which means you either have to make it to quite fine tolerances, or disguise the gaps somehow.

An alternative would be to make the "bottom" in one piece, but then you wouldn't be able to display the (true) bottom of the box from the outside when closed. Does this matter? I feel that it doesn't. After all you can give the "bottom" a solid whack from the inside with the wand when the box is tipped over, and I think that should be convincing enough. But would welcome opinions.

I have never seen anyone show the actual bottom of a tip over box. If you did, that, to me, would defeat the use of this type of box to begin with.

When watching this being performed, one gets the impression they are seeing the entire box anyway when it's "tipped," showing nothing is inside and seeing the bottom of the box that way.

Hope that helps. Mark.

I made a tip over box out of Legos once... Just playing and trying to do a LEGO effect. I ran into the same problem with the bottom.