There is a difference between abstraction and abstract. Not only in the meaning of the words but also in the application of the terms.
In common language abstract is used in both cases. No difference is made between them.
Abstraction is based on a representation of the reality and abstract is a lack of reality. How can photography be abstract? Very difficult because photography is by definition based on reality. Only a photogram or chemigram can be abstract in the strict sense of the word.
Most photos in this exhibition are abstractions of reality, what we call abstract photography.
Are you still with me?