OK so I'm convinced.

Essentially what I consider an Envisage Shift is a type of shift that, although similar to a Phantom Shift, differs in that the experiencer doesn't feel the "physical" sensation of supernumerary phantom limbs. Instead one has a mental imagery and/or a mental awareness of non-existant body parts. Or, having unintentional or unusual mental images doing things AS their theriotype/kintype. Like a phantom body shift but within the mind's eye.

Last part is a bit harder for me to describe but I often do get whole mental pictures of horse-me when I'm feeling shifty.

Personally I feel as though what I experience is distinct enough from a typical phantom shift so I'm gonna use it. Feel free to as well. Or don't if you hate it. *shrugs* Please excuse how clunky this is. I'm not the most eloquent.