This Is Just To Say
I think this poem has to do with temptations, and the plums which the speaker regrets eating are an allusion to the "forbidden fruit."
The form about this poem is very interesting, but I am honestly not quite sure what it means.
In a Station of the Metro
This poem, because it is so short and ambiguous, can be understood mainly by the title; it is about what the speaker sees in a train station.