Generally correct Agx.
The orange and blue/gray lines beneath the distance show the automatic exposure range.
blue-gray is 16 feet, oranges is 33 feet.
The orange and blue-gray in the middle show what aperture to use(in auto)
And the slide switch (M,B/G, OR) allow you to set the power/range.
As an example the flash in picture shows ISO 200, power selected= B/G(f8) and auto range = 16'
For 200 ISO, power set to red(f4) and auto range is to 33'
So, basically, decide the f stop or range you want and set the power. That's only two things to set. Of course set your
camera to it's sync speed and the lens to whichever f stop the flash indicates.
You're going to notice as you change the ISO the calculator will change the distance on the scale but not the lens settings.