Good question.
I believe that is meant as an “original copy”. Manuscripts are usually written on computers these days and then printed out. If you print out two copies they both the original, two copies of the same exact text.
It’s sort of an oxymoron but it also makes sense. I keep three e-copies of my novel on different computers/thumbdrives “just in case” there is a fire or the computer gets stolen, whatever. I can print out from any one of then and it would be an original.
Who is her publisher? I am willing to bet that their copy disappears too.