The discussion centers around a vintage text titled "Tables of Higher Functions," which features hand-drawn mathematical plots. The contributor expresses curiosity about the origin of these illustrations, speculating that they may have been created by an artist with a mathematical background or a skilled draftsman. The timing of the book's publication is considered relevant to understanding the drawing techniques used. A reference is made to Charles Minard's famous Napoleon chart as an example of high-quality hand-drawn charts. Additionally, there is mention of Mathegraphix, a software program for creating mathematical plots, suggesting that the author might have used it for the illustrations in the text. Overall, the conversation highlights the intersection of art and mathematics in historical publications.