If nothing was unclear or difficult, say so. Skip questions about steps you did not experience; use not applicable where appropriate.

What conclusion did the graphic suggest?
Which label was unclear?
What context should accompany the visual?

Author notes / illustrative keys where applicable:
1. Use this answer to locate the part of the experience that needs explanation. The example issue to investigate is: readers mistake a synthetic example for measured results.
2. An unclear label can obscure the variable, unit or population represented in the graphic. Define it alongside the relevant visual using source-backed meaning, rather than inferring comprehension from an attractive presentation.
3. Turn the requested improvement into a testable next step. One illustrative action is: label synthetic values beside the graphic.