I am really curious what his end goal here was. Apple's boxes are all very small — in what situation would a few centimeters in box size outweigh all other considerations?
That last one makes the most sense, and explains why he didn't divulge it. That way, when the author is raided, they aren't going to ask, "hey, where's that computer that, comes in the smallest box?"
I'm imagining the author has this big book case, and one of the books is hallowed out and has an Apple machine in it. Maybe it's built into a false floor of a cabinet.