The Simpson family as they appeared on The Tracey Ullman Show. On the right we have Lisa and Bart, the inspirations for Eliza and Lester.
So, why do Lester and Eliza consistently find themselves at the top of fan's lists of most unsettling Simpsons moments? Why are these two siblings capable of instilling so much fear? On the textual level, these characters tap into a perennial fear of an identical other. Our doubles, who may at any given time, appropriate and remove our senses of identity, remind us of the Lacanian mirror stage; we feel a perpetual disassociation between our true selves and the bodies which we show to the outside world. The conceptual doppelgänger is frightening for this very reason, it highlights not only the disparity between the imaginary and the real but also our anxieties around others not being to perceive our true selves.
The episode's narrative concerns itself with Bart finding the homeless original creator of Itchy, Chester J. Lampwick, from the violently popular Itchy and Scratchy cartoons. Having had his work stolen from him by an untalented artist, yet savvy businessman, Lampwick fell into poverty and would never see any royalties or accreditation for his creation. Inadvertently, Bart's mission to find justice for Lampwick leads to the bankruptcy of the Itchy and Scratchy studios. Bart and Lisa attempt to get their beloved cartoon back on the air, finally coming up with a plan and rushing off towards the studio. The sinister siblings get there first and, by taking Bart and Lisa's narrative role as conflict resolvers, Lester and Eliza already imprint a disconcerting presence. It is worth noting that immediately before the appearance of Lester and Eliza, Marge Simpson reaffirms and recounts all the times Bart and Lisa resolved conflicts such as the one featured in this episode. It is presented as a mother motivating her children to succeed in their task at a moment of weakness, but it also serves the purpose of reacquainting an audience with the format of previous stories. There's really no reason not to think that Bart and Lisa will save the day once again. Yet, as we know, they didn't.
Lester and Eliza, resembling Bart and Lisa, resolve the episode's conflict.
In true Simpsons fashion, Lester and Eliza have solved, alongside the A-Plot of saving Itchy and Scratchy, a B-Plot of Apu's public nudity case/Krusty the Clown's estranged wife. We can imagine an alternate episode that exists within this one, where Lester and Eliza's inciting incident occurs at the cancellation of Itchy and Scratchy, telling its own story to the same resolution. Likewise, we can imagine Lester and Eliza experiencing a similar shock to that which faces Bart and Lisa at the end of this episode, only this shock happening on a far more regular basis, whenever Bart and Lisa's adventures are made public. There may then be an element of personal revenge to Lester and Eliza's appearance. These siblings, who only exist in relation to Bart and Lisa, are faced with the same fear of the double, only their doppelgängers are paraded around town as local celebrities. But what I find more interesting is the notion that Lester and Eliza are not so much characters as they are arbiters, particularly arbiters of punishment.
So, beyond merely the fearsome nature of the characters within their relation to the Simpsons and Springfield, there is a metatextual element that has made Lester and Eliza ring through the audience's mind. It is no coincidence that the designs for these doppelgängers so closely resemble Bart and Lisa's former selves, they tie into the stories themes of authorial ownership and originality. Lester and Eliza arrive to exact punishment on Bart and Lisa- the original versions seeking vengeance on the derivative. With the episode's earlier acknowledgment of Chief Wiggum's derivative status (his voice being an impression of Edward G. Robinson's), the show briefly dips into metacommentary. Bart and Lisa have no right to fight on the side of Lampwick, or originality, as they themselves are insipid repetitions. They are not allowed to succeed, with the conclusion delivering the punishment for their hubris.
The final disconcerting shot of Lester passing by, meeting eyes with Bart, is reinforced by a mind-boggling geography; Bart cannot be looking at Lester, from everything we know about the layout of the Simpson house, yet, look he does. Through the final moments of this episode, Lester and Eliza are repeatedly presented to us as something deeply, profoundly wrong. The distortion of the Simpson house is perhaps the most aesthetically clear realisation of this theme, alongside the Tracey Ullman-esque designs, but the distortion of episode normality, where the audience is prevented from ever actually finding out what Lisa and Bart's resolution to the conflict, is arguably just as significant aspect. Foiling their plan ensures the audience never get the payoff of finding out what their plan to save Itchy and Scratchy actually was, meaning that the episode ends on a dejected whimper, rather than any triumphant victory.
Bart looks out of the rear-house window to see Lester in the view of the front-house window.
Bart ends the episode with a comment on how unsettling it is that he and Lisa weren't the ones to solve the conflict. Here he speaks for an audience who are, for a change, suddenly challenged and made uneasy by The Simpsons. Lester and Eliza's fearsome nature, in their minuscule time on screen, is played up, so as to exist properly as arbiters of punishment. Not satisfied with merely stealing the joy of victory from Bart and Lisa, the arbiters of punishment go so far as to steal their individual identities and the natural order of their world.
"The Day The Violence Died" is a deeply affecting, profound episode, even if all the elements which make it so only occur within the final minutes of the story. It taps into something primal and existential. Bart and Lisa would, of course, go on to have more adventures, paying this experience no heed, but the visceral, lasting effect this throwaway gag has had is worthy of note.