The use of the word 'pictorial' in critical writing on photography generally refers to more illustrative compositions - i.e. one point perspective, near-far, little emphasis on formal elements (no abstraction of space). Most amateur landscape photography you see prescribes to pictorial methods. 'Pictorial' means *compositional* devices derived from painting, basically.
'The Pictorialists' or pictorialism on the other hand was a movement in photography that not only used pictorial compositions, but attempted to emulate painterly, impressionistic effects through photographic techniques.
So I assume you mean 'pictorialism uses abstract concepts', but... pictorialism is only abstract *in technique* if we consider straight photography the norm. In actual fact, f/64 and Edward Weston's work in particular would have been considered abstract in its nature and thinking at the time. F/64 paved the way for formal abstraction in photography through proposing that an 'intensity of seeing' is more important than effects in technique.
Pictorialism at its core is illustrative, with the 'fuzziness' adding the mood and emotional elements.
Coming back to contrast and what Thomas said about negative space (pure black or pure white) being used as formal compositional elements - something Bill Brandt did a great deal. Although this is a product of photographic technique it has all its roots in f/64 because it is informed by seeing and in turn, the abstractions of seeing. Pictorialism had no part to play in the use of contrast as aesthetic.
Yes, I mistakenly left off the "ist".
The point I'm making regarding Pictorialists leaning toward abstraction is that Pictorialists aren't necessarily or even normally trying to picture anything "straight".
Also f64 has no lock pre-visualization or seeing.
Mark Barendt, Ignacio, CO
"We do not see things the way they are. We see things the way we are." Ana´s Nin