A first impression is useful evidence of your response, but it is not the end of looking. For photography credited to Roberts Voskans, spend a few moments with the complete frame and record what draws attention first. Then examine one quieter area and return to the whole. Notice whether the centre of interest changes as you discover additional relationships.
Revisit the image after looking at others in the same selection. Repetition, contrast or sequence may make a previously minor detail more significant. Describe that change without assuming it was planned to produce exactly your response. A careful account can say both what is visibly present and how your attention develops, leaving room for another viewer to follow a different route.