What is Saki's attitude toward Mr.Nuttel? What is his main purpose for writing "The Open Window?"

Saki seems to portray Mr. Nuttel as a weak and pensive man from the city. For the most part, Saki's use of the third person in his narration delivers a bland, matter of fact view of Mr. Nuttel. It is, however, amusing when Saki describes the Mr. Nuttel’s fear and naive when Vera tells him her story.The author's purpose was to amuse his readers.