It doesn't fall into improving physicality. I would say the better/more of your body you can recruit to do a given task, the more efficient it is, although in this case, efficient might not be the right word. Spoons are light objects, lifting it taxes the system very little.
I think I understand where you are going:
Internal= better organization and use of the body.
External= making the body bigger, stronger etc.
Is that a fair assessment?
Hmm, something seems wrong to me about this division, because in my experience a lot of athletics, and certainly the majority of aikido that people appear to be calling 'external', is about using the body more efficiently such that less force is needed. E.g., using momentum, gravity, leverage, relative positioning are all often called 'external' in the discussions I've seen, yet the whole point of them is efficiency and efficacy so that the body doesn't have to be bigger or stronger.
So that makes it seem to me that this definition isn't quite on the mark yet.