We generally don't allow design-only questions.

A question has been asked that provided review-able code, and depending on your POV an additional question is asked about 'maintainable modular code' in general. Now, that is definitely more design-related than code-related, and in my answer I have opted to focus only on the coding.

There is now a design-only answer for the 'maintainable modular code' part, but nothing on the code itself. This is different from providing a non-code answer that still focuses on the code aspects (e.g. when one isn't familiar with the target language, and prefers to outline in words/pseudo-code).

How should we handle this? Leave a comment for the answerer to see if they want to edit their answer to also talk about the code parts? Flag it? Or is the question itself off-topic in the first place, and we should get OP to clarify the intention first?