I think I totally misunderstood your question.
If you’re asking why is there white around the text when the security paper should be there, then I would guess that it’s an artifact of having created an electronic document from a physicial sheet of paper.
Yes, that was my question. So copier with a green hashed paper would not produce the white around the letters, but digitizing that piece of paper would (more or less depending on how it was digitized). It seems very odd that we would not a high fidelity picture of the original if it were made by a copy machine with green hashed paper. Any $50 camera would produce an image without white around the letters.