And usually such transactions are heavily covered by law for the very reason that the paperwork can be deliberately obfuscated. If you buy a car, for instance,

And usually such transactions are heavily covered by law for the very reason that the paperwork can be deliberately obfuscated. If you buy a car, for instance, or you buy anything on credit, there are clear legal requirements for what has to appear on your receipt -- because it can be so misleading. As a side note, I'm really sorry I used the word "deceive", which implies intent. Misleading is a much better word. I don't think there was any malevolent intent in that graphic at all. There are a couple questions here: first, is the metaphor being used appropriately? I think not. I think it could be done a lot better. Second, does the metaphor of a receipt even work enough to be useful at all? I don't know, but if you want to try to use a metaphor for cognitive leverage on this particular problem, a receipt is probably the best thing you've got. As computer guys, we have to deal with and talk about complex systems all the time. Using metaphors is part of that. It's probably the best tool we have. The reason I commented in the first place was to show that if you pick up a metaphor, you have to run with it as far as you can, then clearly point out where the metaphor no longer works. To do otherwise is to invite a lot of confusion, and, well, to be misleading.