Sorry, Mate.
I've just, finally, realised what you were getting at with this drawing.
I thought it was meant to represent the Nile Valley with 'mountains' down either side, and that's why I was so dismissive of it.
I see what you mean by the perspective making it look like a stairway to heaven

)) and while It looks good, I still have some doubts about it being an effect that was intended from the outset.
Apart from anything else, the illusion wouldn't appear until after you'd built the thing. Even if the designers had predicted it, that's a lot of work to do just to see if the illusion really worked.
The other thing is that the evolution of Pyramid building is easy to trace, and the earlier step Pyramids and low-angle Pyramids wouldn't have produced the effect, so it wouldn't likely have occured to anyone to try for it in later versions.
Again, apologies for misunderstanding earlier.
Ankh udja seneb