This is just an oddball observation from reading around about the show.
Later on, I learned the old story of the Nightingale from somebody that knew it. The tale was a fable about an emperor of some ancient country, who loved the song of a mechanical bird.
Episode 2: Dorothy Dorothy
(Naming the informant character “Big Ear” is probably a reference to the character from Thus Spake Zarathustra.)
This is referring to The Nightingale by Hans Christian Andersen:
The Emperor of China learns that one of the most beautiful things in his empire is the song of the nightingale. When he orders the nightingale brought to him, a kitchen maid (the only one at court who knows of its whereabouts) leads the court to a nearby forest, where the nightingale agrees to appear at court, where it remains as the Emperor’s favorite. When the Emperor is given a bejeweled mechanical bird he loses interest in the real nightingale, who returns to the forest. The mechanical bird eventually breaks down; and the Emperor is taken deathly ill a few years later. The real nightingale learns of the Emperor’s condition and returns to the palace; whereupon Death is so moved by the nightingale’s song that he allows the Emperor to live.
The moral of this fairy tale is pretty straightforward. If you give up the real thing for an artificial, symbolic representation of the thing (i.e. the super-excitation of hyper-reality), like drinking corn syrup instead of eating fruit, then eventually your malnourished soul becomes too unhealthy to even enjoy the simulation anymore. The connection between the representation and that which it represents breaks down due to the disgust of overexposure, and the only thing that can save you is the holistic nourishment of the real thing again.
(See also: anhedonic hyperphagia in rats presaging pathological virtue signalling in behavioral economics.)
Since the show appears to be a commentary on post-modern epistemology using the simulation theory of the universe as a metaphor, it will be helpful to understand the role Dorothy plays in the referenced fairy tale.
She is a mechanical recreation of a girl who died before Paradigm City lost its memory and is shown singing in this episode (helpfully named “Dorothy Dorothy” so we understand it’s establishing her character). This is a pretty good indication that she’s supposed to be the nightingale. On the other hand, she stays in Roger’s mansion as his maid, like the maid who led the court to the nightingale, which would indicate that she may not be the symbol or the real thing so much as that ineffable strangeness which guides us to the real thing outside the articulable walled garden of civilization. This would be thematically consistent with Chiaki Konaka’s use of red-haired girls in Serial Experiments Lain and especially Technolyze, and is likely meant to evoke the Western trope of red-haired women as representing mystery.
I haven’t figured out what “real thing” Dorothy would be leading us to but this is a decent starting place. Probably something to do with Nietzsche and epistemology. Right now I’m toying with the idea that The Event refers to the death of God somehow, but so far it’s a pretty hazy association and it wouldn’t fit with my previous association of memory with genetics.