I believe you are confusing pre-planning a shot with visualization of a photo in front of you.

Your example of the man and the hat is an example of planning a shot without knowing all the parameters possible.

Visualization would take place when the shot is in front of the photographer.

1. Exposure - high or low.

2. Contrast - will there be needed contrast adjustment in exposure and development (chemistry development),

3. Will it be a verticle or horizontal?

4. Composition and the use of space - fill it or use negative space.

5. How will the image present? Color? Rich color or muted color? Black and White or tinted monochrome.

Visualization is seeing the end presentation of the image in front of the lens, it is not pre-planning a photoshoot.

Although that can be very important as well.