So-called because her body is oriented perpendicular to the traditional vertebrate long axis. There's no major conceptual basis for this one; it was actually an image flash inspired by dried paint splotches on the palette I was using for acrylics last week. One of them struck me as the sort of patterning you might see on a right whale, but the impression I had was of a vertical, and laterally flattened, body arrangement similar to that of an ocean sunfish (Mola mola).
The markings as I originally interpreted them were more involved and more highly contrasted, so there may be another version of this in the future. In fact my original image more closely resembled another type of whale I can't quite harpoon right now, so I'll look through some marine mammal books tomorrow.
Alternate history, far future, transplanted panspermic hybrid...? It's your call!