Thumbnail comparisons become misleading when one draft is displayed larger or against a more favorable background. A fair visual review starts by controlling these presentation differences.
Standardize the view
Place both exports at identical dimensions with the same surrounding background. Use the same title beside each if you are evaluating image changes only. Label the files neutrally so their names do not imply a preferred version.
Ask a specific question
Compare subject recognition, label readability, or accuracy of the promise. Avoid asking which is better without defining the goal. A more dramatic image may be less informative for a practical tutorial.
Keep the conclusion narrow
Record what changed and why one version was easier to understand in this review. Do not describe an informal preference as a proven performance winner. Save both files with the decision note so a later audience test can distinguish the original hypothesis from measured results.