The MidJourney-style 4-up choices is a powerful UI paradigm.

For image generation, it's the best way to steer the generation through the latent space.

But it actually makes sense as an iteration style for any movement through a state space.

For example, imagine a code artifact, and a series of diffs to modify it.

A knowledgeable user might be able to create a bespoke diff that matches their intuited direction of travel.

But a less knowledgeable user might want to tell an assistive technology what their intent was, see multiple possible diffs, and then pick the one that seems most in line with their intent.

A 4-up is also much more forgiving for lower quality.

As long as a good enough answer exists in one of the four options, then the user is satisfied (at least to sit through another round of iteration).

If you only had one option, the likelihood the option was good enough is significantly lower.

Imagine the likelihood of a good-enough-quality generation is 70%.

For a single one, the chance it's bad enough quality to get the user to give up is 30%.

For a 4 up, it's 0.8% (0.30 ^ 4)

The 4-up also allows giving more variation, which allows the user to lean into the one that feels most right to them, giving feedback that might be hard to articulate in precise terms.