Questions about face category boundaries

Our portrait form needs a basic consistency check before we discuss its face shape categories. I want to distinguish a different crop from an actual change in the visible facial outline. My starting set would contain one portrait used with permission and a note of its original size. I would vary the border area while keeping the actual facial geometry unchanged in every copy. I am considering face shape detector as a reference while drafting the questions. These are proposed checks rather than results, and I have no consistency figures to share. A useful record would include the crop, the returned category and any stated uncertainty. Which observations would help distinguish a crop sensitivity issue from an unclear face boundary? My priority is a clear account of changed outputs, with room for genuinely uncertain classifications.