I agree with Per (surprise, surprise), and there are many phases in the art of making a photograph. I consider seeing (=visualization) and previsualization to be quite independent of gear.
Offhand I think there are typically five or six steps in my own path, like this:
-previsualization (sometimes, not always)
-visualization / seeing of the actual candidate subject (and at this stage, ~75% of the time I decide *not* to take a photograph, i.e., no camera is deployed)
-composition (this is where the equipment and format enters the picture, for me)
-execution of the photograph (obviously gear and format plays a large role from here on)
-imagination of the print
-execution of the print
-posting to APUG
So if the question had been regarding
composition, well then I would say that is a lot more related to the equipment at hand and format. I find it a bit hard to compose, mentally, without invoking a specific aspect ratio, etc. The viewfinder affects my composition.