[additions, small typos fixed; picture-links added 28/03/2015]
First, I’m way past needing any convincing that MS Beinecke 408 ain’t a mainstream Latin work, but that’s because in addition to the “background image” of what mainstream illuminated mss look like compared with what MS Beinecke 408 looks like, I’ve done several years’ deeper research. And the results are perfectly consistent across every section and almost every image: NOT mainstream Latin Christian and in any case … German?? I think not.
What informs that “background image” is made up of all the examples you’ve ever seen of one tradition in art, and it’s not just about how they draw the princess in the pumpkin-coach, it’s why they think a princess is worth putting in a picture in the first place … and a pumpkin… It also has to do with what the original readers thought and were expected to see in such a picture etc. etc.
People draw their idea of the things which make their world beautiful, important, interesting, or useful.
Now, if you run a survey of western medieval manuscripts emerging from the Latin tradition, you could do frequency diagrams to get the results more exact, but the top 10 types of images in western Latin (Christian) illuminated mss on membrane made (say) 1250-1450 would be:
Man with crown
Man on horse (or more than one, with or without crown/s)
Man with armour and sword.
Men killing each other in one way or another.
Women looking beautiful, enthroned. (includes saints, queens etc.)
Women looking like normal people, often pretty, shown talking together while doing (a) nothing but being nobles, (b) shopping, (c) other small chores.
People engaged in the hunt – for people, or for animals.
People being saintly and/or martyred.
People performing Christian ceremonies and rites.
Plants – shown with persons and/or animals (even in many herbals).
Metaphorical creatures – inc. heraldic animals, angels and mythical peoples such as Gog and Magog.
Ok – that’s roughly what I’d expect to be the top ten sort of image in a western Latin-Christian manuscript.
check this list of 10 top themes against imagery in MS Beinecke 408. Different world-view, different priorities – just not part of that environment.
But now, look at pictures in the Florentine Codex.
See what I mean? Not so pretty, but very similar emphases: Men, war, war-costume for men, kings, women’s daily chores…
Another detail – Fray Sahagún very often gives the faces (especially but not only the males’) a long, slender nose noticeably similar to his own. Here is an example from the Florentine Codex; here is his portrait.
The Florentine Codex is a manuscript which you could certainly pick as one informed by European priorities and Christian attitudes, even if not originating in them. Not so for the Voynich manuscript which doesn’t reflect the dominant culture of medieval Europe. Different idea of what is worth setting down in pictures, and a general avoidance of any realistic-looking human form – or animal either, for that matter.
So no, not convinced.