I did write a lengthy (nice) response to try to better articulate my own subjective experience for comparison so we could continue to try to better understand one another but then I kinda just lost faith in the idea…
Do you possibly speak more than one language to any degree? If you think of the words “yes” and “oui” (yes in French), there must be some difference in what you experience inside your mind despite the meaning being the same. So what is different between the two subjective experiences for you?
AFAIK whilst some creatives do fully conceptualise the work in their heads then set out to externally reproduce it, the more normal approach is to have a less complete notion and then create something via the process. IE, a musician might have a melody in their head but then they will play it on the instrument and experiment with different variations and accompaniments to see what sounds good and build on it that way, rather than sit and think of an entire piece based on that, then play it out loud.