The diagrams illustrate how cutting equipment changed in 2 periods of the Stone Age.
Overall, there are 3 views of each tool (Tool A and Tool B), and the older version looks relatively sharper and darker compared to the latter one while maintaining the same hight.
1400 thousand years from now, the tool A was in a triangle shape based on the front view, while 600-thousand-year development changed the shape of the equipment from a triangular to more circular or oval and brighter gray. From the side view, it can be observed that the tool B lost its depth, making it 2 to 3 times thinner, and the colors look almost exactly, however. The back view reveals how it relatively similarly changed like the front view, the same in the shape (from triangular to more oval) and in the color (from darker to brighter gray). Lastly, the height of the tools did not experience any change (at 5 cm).