Alphabetic Text as the Only Text

I’m befuddled by this MLA call for proposals for a volume on the Changing Role of Writing in Composition.

Everything I understand about multimodal texts tells me that any alphabetic text is not tapping the linguistic mode alone; but from reading this CFP, you’d think that spatial and visual modes (for say a paperback book) weren’t a thing until this “turn toward multimodality.”

I’ve read and reread the call, trying to figure it out. I thought maybe I was just not getting something (blame imposter syndrome). For the life of me though, I can’t figure out how to respond to that while talking ONLY about alphabetic text (which is culturally limiting in addition to not making sense in a multimodal context). I’d really love to submit something to the call; but I can’t figure out how to work within such a limited vision of what it is to be multimodal.

 
Image: abc album p1 by patricia m, on Flickr, used under the CC BY-SA 2.0 license.