You have only convinced me that the letter in question was so designed by a clever graphics person as to present itself as a “Z”, on purpose.
You want to believe that the design presents the letter as an “E”, and by faulty design of the designer, instead presents itself as a “Z” not only to discerning eyes on a good computer screen, but to all eyes when enhanced and greyscaled, as others did to the entire phrase. It says; “Z Pluribus Unum”.