Verdict
Prototype addresses a common agent failure: converging on the first plausible UI and presenting cosmetic variants as exploration. By requiring materially different directions in a live picker, it turns subjective design choice into a fast comparison rather than a long prompt negotiation.
Best for
Components and interaction patterns where the product direction is unresolved and seeing several working alternatives will reveal more than discussing abstract preferences.
Keep in mind
It must be invoked explicitly, and variant exploration costs more implementation time than selecting a known pattern. The picker helps compare directions but does not replace user research, accessibility checks, or production hardening.
Example task
Prototype three genuinely different approaches to a hold-to-delete control and put them behind a picker so we can choose by feel.