Anyway, I think the "manuscript" is what its text is. (Unless it is not argued that the text is unrelated to the imagery).
So if we talk about it being a copy of old sources, this should mean that the text is a copy as well. If only imagery is a copy (and the more so, only part of that), then one cannot say that the "manuscript" is a "copy". It is a derivative work then, - or an encipherment at most, - which hypothesis (the derivative work) I have no problems with.
So if we talk about it being a copy of old sources, this should mean that the text is a copy as well. If only imagery is a copy (and the more so, only part of that), then one cannot say that the "manuscript" is a "copy". It is a derivative work then, - or an encipherment at most, - which hypothesis (the derivative work) I have no problems with.