So, to make this more obvious, some detail needs to be added. I'm doing this in goldwork, using the same threads as for the rays.
First, I outlined the edge of the first 'leg' of the trilithon:
As with the rays, this uses four strands of the gold thread, couched in two lots of two.
I then added a vertical line in gold, to highlight the perspective:
It makes a big difference, doesn't it!
It should make an even bigger one once the other leg and the top are done - they're next.