Oscar Jubis writes:

Here is an exerpt from Donald Spoto's book, "The Art of Hitchcock".
"Vertigo also comments on the metaphysic of film, and on its power to affect the psyche. The love which it examines is the fruit of illusion and human artifice, just as a woman's appeareance in a film is the fruit of illusion and human artifice - 'everything is fake'...

Indeed. VERTIGO can definitely be read as allegory.
David Thomson says something like this too. He speaks of: "Rear Window and Vertigo, superb commentaries on watching films."

It seems that when he became aware of Ozu, Thomson decided that Kurosawa had been overrated. I don't know how he got that idea. You won't find me dissin' Kurosawa.