Question

برجسته ترین نکته فضاسازی داستان بود

Answer 1

The most noticeable point in the story was its setting.

OR: Scene-setting was the most salient feature of the story/novel.

OR: Setting the scene was the most remarkable feature of the story.  

Answer 2

The  outstanding/most prominent feature of the story/play was its mood/atmosphere/mood & atmosphere.

To create atmosphere or mood means that the audience engages in emotional and intellectual activity when confronting the relationship between mise-en-scène and dramatic action at a particular moment in time.