How do you describe an oval face without rigid rules?

[Miaor]

A short reader quiz on my editing desk asks everyone to select one face shape immediately. At the moment, the descriptions for oval and oblong overlap enough to leave me unsure what to change. I want to make the wording clearer without promising that every reader will fit a single category. I have bookmarked oval vs oblong face shape as a comparison reference for the revision. Would it be better to ask about visible proportions before introducing the category names? There is space for an unsure answer and a short note about the limits of the categories. I would like the descriptions to stay neutral rather than rank the possible answers by appearance. We have room for a small diagram if the caption makes the intended comparison clear. Which part of the question would you revise before adding more possible answers?