In "This Is Just to Say", the speaker focuses on the moment he let temptation get the best of him by eating plums that were being saved for someone else. We can see humor in this poem as it takes the speaker a long time to apologize, and he seems to prove that the poem can be a non-apology when he emphasizes how delicious these plums were.
In "l(a", the speaker emphasizes loneliness by comparing it to a leaf falling by itself. The form is important because it shows fragmentation of words that visually illustrates separation. Looking at this poem vertically and horizontally gives us a clearer picture of the theme of the poem. Horizontally the peom says l(a leaf falls) oneliness. Looking at this poem vertically shows that shape of the poem resembles a 1.
The speaker in "In a Station of the Metro" expresses a common rhythm of nature as he describes the constant flow of people leaving and entering the metro. We wouldn't find this crowded station so pleasant, but the speaker is in a peaceful, relaxed mood. For him, the people from the metro aren't just a bunch of faces, but they are more than that because to him they look like beautiful petals. The speaker finds natural beauty in his surroundings, and he has imagination and patience to think about a single image to figure out what it means.