mentally I think
I think that when I (as a trionian) would somehow find myself in Tetronia (ie some tetronian world) I would be able to easily change my trionian viewpoint from {x,y,z} {x,y,w} {x,z,w} and {y,z,w} and must somehow mentally make the connection that those views represent the same object.
My trionian perception can only view one of the above mentioned views at a glance, being able to shift quickly from views can be very helpfull in establishing my mental picture.
You might imagine having 6 seperate pictures of mere squares with colored edges, when those same pictures are on a single sheet, it will be more easily to view them as representing the same cube, certainly when they are layed out in the way a papercube can be constructed from them (ie the 3,1,1,1 layout or simular)
As a tronian I can percieve 3d object at a single glance, be it that I can only see three faces at once of say a solid cube