Bird's-Eye

This isn't a low-level idea; hell, it's about as high level as you can get:

...wouldn’t it be neat if we could do a weekly bird’s-eye printout of the source code and pin it up on the wall, giving a nice simple visual representation of the simplification of the code?

Having visibility over all the code does sound mighty useful. It can be difficult to see the overall patterns in the source when working on a single area. The more visibility, the better, right?

Granted, what you can see from this bird's-eye view might not be that useful. At such a small scale, really all that might be possible is spotting the various rat's nests of code. Those big blocks of if-if-if-else-if-else-if-if-else-else-ad-nausium spaghetti code certainly would be easy to see and, hence, make for easy refactoring targets. Once the process of identification and refactoring is done the actual pictures of code is pretty uninformative - the code may look clean, but the text is still too small to given any detail about structure.

Of course, the author suggests this as a method for easing the refactoring of legacy code. After the project has moved beyond the legacy-code phase, the value of the bird's-eye method is diminished to a simple tool for preventing spaghetti code. A lot of paper updates, for a little gain.