i was thinking that it relates to the 4 corners of the house of troubles if anything.
That has a lot of obvious plausibility. I would also suggest the four corners reference the four quadrants of the world, or (to reference the lessons) the five corners of the world (minus one). One question is to what degree these might correspond - what role do the four "bad" daedra play in the creation/mythical structure of the world in the mythology of the Tribunal Temple?
There's also the further question concerning whether the four corners reference anything else, viz, real world superstition, etc. Unfortunately I'm not competent in those areas.