Something where the person that is going to be using it can't easily define the full set of requirements in one go because they're going to need to interact with it first, and subsequent requirements will emerge after use. The limitation in this case will not be the AI's ability to implement what was requested. It will be the human's ability to articulate what success looks like.
Well yes, if you can’t articulate what you need then it’s hard for anyone to build it right on the first try.
Otoh I’d say the current models are better at predicting expectations than average programmers. Average programmers don’t know ux or business, LLMs do.