Agreed. I worried that this might be yet another example of printers and scanners doing strange things, like <https://en.wikipedia.org/wiki/Printer_steganograph

Agreed. I worried that this might be yet another example of printers and scanners doing strange things, like <https://en.wikipedia.org/wiki/Printer_steganography> https://en.wikipedia.org/wiki/Printer_steganography> or <https://en.wikipedia.org/wiki/EURion_constellation> https://en.wikipedia.org/wiki/EURion_constellation>. Glad to see that this can be ascribed to incompetence rather than malice.