Most of the sketches are based off of simple grid designs like single-column and two-column. The reason being is code and the image (application) it represents are often very abstract and not so much artistic, so anything fancy doesn’t really suit the subject.
Spread 1 is pretty much single-columned with two rows with alternating code and application screenshot it represents. The contrast between black and white is symmetric with respects to diagonals.
This spread has a more unified look with all the code on one page and application screenshots on the other. This look is easier on the eyes as it clearly separates the implementation from the view.
This design is multi-columned with two columns of code as background, but with screenshot overlay-ed on top. It’s a interesting design, but may not be suitable for the subject matter especially for those who actually know the code, as it’s distracting.