Given the list of reference works in their bibliography, it's surprising that the list of visual illusions isn't more extensive. It was interesting to see sections explaining how proximity creates illusions of scale and makes people group together objects which are simply near each other. Still, the text doesn't suggest much more about where these habits might lead in practice. It does include an excellent example showing that all dials in a airplane are oriented the same way, so that any dials with unexpected readings will immediately pop out.
The wild variability in the visual examples made it visually exhausting. I nearly missed a few excellent but "less noisy" examples. I also regret not plumbing the bibliography before dropping the book. But the authors did guarantee me that the same weight will seem heavier in a smaller bag.