The claimed Voynich page

[Jorge_Stolfi]

I don't know if this has any implications for exactly how this may have been copied.

If the new vellum is translucent, the copy could have been sketched by placing the new vellum over the original and tracing the main parts.  In this case the text and plant should have exactly the same size and relative positions.

But the copy may have been made with a camera lucida, in which case the scale may be different, and there may be some perspective distortion (the "Star Wars Title" effect).

All the best, --stolfi.