Mark, if you picture the rosette as an aerial view, then the arches would have to curve inward to fit the circle motif.
Also, courtyards are not always square, some are hexagonal (I've seen an extremely beautiful fountain-garden courtyard that was hexagonal). Plus the whole rosette page is done in a circle motif. In medieval drawings many things that are square in real life were drawn as circular (especially gardens) and schematics (like Lullian diagrams) were very frequently circular.
I don't think it has to be all cosmological or all literal. I've blogged about the possibility that the outer corners might be literal (the material world) and the ones at positions 2, 4, 6, and 8 (and possibly the center) might be cosmological. In other words, a drawing in two planes. Even this has an analog in 16th century drawings, in which the literal and cosmological were seen as "layers" (I posted an example). I think the center might be the meeting point between the two (like a church/temple/synagogue or some place like Rome or Jerusalem, for instance), which is where the material and spiritual realms meet.
Also, courtyards are not always square, some are hexagonal (I've seen an extremely beautiful fountain-garden courtyard that was hexagonal). Plus the whole rosette page is done in a circle motif. In medieval drawings many things that are square in real life were drawn as circular (especially gardens) and schematics (like Lullian diagrams) were very frequently circular.
I don't think it has to be all cosmological or all literal. I've blogged about the possibility that the outer corners might be literal (the material world) and the ones at positions 2, 4, 6, and 8 (and possibly the center) might be cosmological. In other words, a drawing in two planes. Even this has an analog in 16th century drawings, in which the literal and cosmological were seen as "layers" (I posted an example). I think the center might be the meeting point between the two (like a church/temple/synagogue or some place like Rome or Jerusalem, for instance), which is where the material and spiritual realms meet.