Perhaps it would be best if you imagined it as your own fancy bids, assuming it will rise to the occasion, for certainly I cannot suit you all. For instance, how about technology? I think that there would be no cars or helicopters in and above the streets; this follows from the fact that the people of Omelas are happy people. Happiness is based on a just discrimination of what is necessary, what is neither necessary nor destructive, and what is destructive. In the middle category, however--that of the unnecessary but undestructive, that of comfort, luxury, exuberance, etc.--they could perfectly well have central heating, subway trains, washing machines, and all kinds of marvelous devices not yet invented here, floating light-sources, fuelless power, a cure for the common cold. Or they could have none of that; it doesn't matter. As you like it....I fear that Omelas so far strikes some of you as goody-goody. Smiles, bells, parades, horses, bleh. If so, please add an orgy. If an orgy would help, don't hesitate. Let us not, however, have temples from which issue beautiful nude priests and priestesses already half in ecstasy and ready to copulate with any man or woman, lover or stranger, who desires union with the deep godhead of the blood, although that was my first idea. But really it would be better not to have any temples in Omelas--at least, not manned temples. Religion yes, clergy no. Surely the beautiful nudes can just wander about, offering themselves like divine soufflés to the hunger of the needy and the rapture of the flesh. Let them join the processions. Let tambourines be struck above the copulations, and the glory of desire be proclaimed upon the gongs, and (a not unimportant point) let the offspring of these delightful rituals be beloved and looked after by all.--Ursula Le Guin, Walking Away from Omelas.
Before the quoted passage, the narration starts with a description of the Festival of Summer, the physical geography and architecture of Omelas, some of its political and religious institutions (although the narrator suggests lack of familiarity on both), and the happiness of (nearly all) its inhabitants. The narrator also calls attention to the fact how difficult it is aesthetically and rhetorically to convey happiness in light of (as the narrator notes just below the passage I have quoted) "modern tastes." In fact, in addition to an (incomeplete) characterization of Omelas, the main pre-occupation of the narration op to this point is (recall this post) the nature of (modern) narrative itself (and the characterization of genre).
In the quote, the narrator explicitly calls attention to (a point much emphasized by Socrates in Plato's Phaedrus and, if it is authentic, the seventh letter) the fact that a written text must accommodate itself somehow to a diversity of souls (who may be unknown, but anticipated by the author) or (if you prefer less metaphysics) to human heterogeneity in aesthetic and other engaged responses.+ The narrator doesn't merely explicitly admit she (why not!) may not be able to satisfy all her readers, but she also invites, no challenges ("rise to the occasion") her readers to use their own imagination to constitute a version of Omelas that will satisfy their image of a happy place. These are souls that assume a happy place must have technology (trained on, say, Bacon's New Atlantis) and lots of freely available sex (trained on, say, Brave New World). Of course, the narrator isn't just inviting readers to develop their own version of Omelas with accidental properties inessential to the true nature of Omelas, while simultaneously revealing that these properties may be essential to the kind of readers they are. The narrator is also calling attention to the fact that she is aware that she may disappoint some of our expectations; may, in fact, disapprove of our expectations (e.g., we want to be able to blame organized religion for the cruelty at the heart of Omelias; we want a narrative of technological progress or out of control desire and so blame these, etc.).
The issue of the politics of readership (see this very important paper by Julie Klein) raised in the previous paragraph is not just a matter of aesthetic and intertextuality (or meta-fiction); it also bears on the nature of how to understand the psychomyth (HT John Holbo's very fine piece) that Omelas is. (Psychomyth is Le Guin's own term.) A psychomyth is a certain kind of thought experiment, which is the occasion for (to quote Williams James) “a specifical and independent sort of emotion.” For, Walking Away From Omelas, shows two kinds of characteristic responses to the cruelty at the core of Omelas. Two natures are revealed: (i) those that stay and embrace the misery of the innocent child as a necessary feature, "the terrible justice of reality;" and those that (ii) quietly leave town (that's the closing "incredible" paragraph of the story) keeping their hands clean.*
As an aside, both (i) and (ii) do not violate the terms of the social compact that gives Omelas its social structure. (The only difference is that the group of folk that belong to (ii) refuse to go on to benefit personally from the contract.) This social compact (which almost certainly precedes the narrated time) is grounded in the opinion of all. (In this sense the social compact mimics Hobbes's unanimity requirement.)
Even so, and to return to the main argument, and as it happens, (iii) anyone could bring "the child...up into the sunlight out of that vile place"** and so destroy the social compact which is thought to bring happiness to all. Such a noble soul would have to be willing to reform society's institutions against the common understanding of happiness. That is, as the Cave analogy emphasizes (in Kristie Dotson's felicitous summary) worldviews are resilient against change.and very difficult to disrupt (especially if they characterize the truth of the phenomena). Even those that recognize the abhorrent truth have incentives to exit rather than to change the social status quo. If they are humane they may well wonder if acting on their perception of wrong isn't reckless given that the downside risk is carried by all of society and there is always a possibility that their perception is wrong. (This is why revolutionaries often seem like fanatics.)***
By treating the structure of the story as a reverse Utility Monster (and so the standard case), we may miss the third character as a live option. It's not a live option in the sense that one should expect to live in times when they naturally pop up. Le Guin's narrator is more plausible by effacing the very possibility. But by insisting that how we respond to the narrative says something about how we might be, we are also encouraged to cultivate in ourselves habits of thought, and, perhaps shared systems of thought, that make possible efforts to resist resigning ourselves to given options.++