...she is fulfilling her role as a housewife as the narrator observes...

...then she comes to the curb (her sea perhaps?) and becomes overwhelmed with openness...

...her sexual appetite piqued. She has awoken to an extent. However, it has damaged her in the narrator's eyes...

...to the point where he sees her as nothing more than "a fallen leaf"

I wasn't really getting that impression, but then again I wasn't really understanding the underlying message of the poem. I looked up...

some analysis (www.english.illinois.edu... & they seem to think the man in the car lusts after the housewife. I'm not sure what to think.