Sen, 39, is making her Bengali film debut with the film.
"Sushmita has a perfect Bengali diction, perhaps better than many other Bengalis here. We bonded well and she could guess what I was looking for as a director," Srijit said.
"Nirbaak" (speech-less) has four stories stringed together by Sen's character which bears no name.
"In the script the woman can't be easily defined, she is beyond that. You will understand what I am talking about once you see the film. In the film Sushmita is referred as 'The Girl' and 'The Woman' variously," the director said.
"I had thought after seeing the painting what would happen if that very tree would be overpowered by human passions and react in the same way - by loving, showing anger, and emotions!" he said.
"Nirbaak" will release tomorrow.