This question takes it beyond the personal evaluation of one’s own work to the critical analysis of the techniques and styles that are used by others. It’s important to be able to clearly articulate preferences when it comes to front-end development, so this question will put them on the spot.

One thing to note here is that the developer would need at least half an hour to review the page and its underlying implementation, so it’s usually better to tell them up front that you will be asking this question.