I have driven straight, lens shaped blades off, up to five inches long, but those were occasional accidental results while trying to reduce a core. To do so deliberately, side by side, is beyond me, at this point anyway.
With the flakes they took from the side, it makes me wonder if the first one dove, and they removed that entire section to make sure the next did not follow the same path.
Other than that, I can find no reason for the steep flakes taken on the left hand side. Those flakes feather on one edge, but the other edge has a square step along the entire edge. Not quite sure how you would repeat that pattern either yet.
I would love for someone like Marty to examine it, and see how he thinks it was done.