Now shine your light on the test object so the camera stops down. You can check for the small f8 setting visually. The focus will be even better now. This proves that macro mode involves something more than just stopping down. I think that what is happening is really stupid or very clever, depending on your point of view.
All macro mode does is move the CCD back farther than the normal range.
The designers may exclude travel in that range normally because it would increase the focus time when looking for best focus. Then to get closer, you have to be f8, to get the pinhole effect. If it isn't f8, it puts up the shaking hand. The camera seems to do a pretty good job of squelching the flash in macro mode so that you don't overexpose. You can still take a neat low light shot though.