Final answer:
The flashback in the text reveals Framton's character traits, hints at a shared history between Framton and Mrs. Sappleton, and generates suspense by revealing Framton's deception.
Step-by-step explanation:
The flashback in the text has multiple effects on the story. Firstly, it reveals that Framton is a high-strung person who doesn't enjoy socializing. This helps to establish his character and personality traits.
Secondly, the use of flashback hints at the history between Framton and Mrs. Sappleton, suggesting that they have a shared past. This adds depth to their relationship and creates intrigue for the reader.
Lastly, the flashback shows readers important information about Framton's intense fear of dogs, which becomes relevant later in the story.
It generates suspense by revealing that Framton isn't telling the truth about his past, leading the reader to question his motives and actions.