| I listened with heart fit to break. (5) |
The speaker's passivity at the beginning of the poem is pretty extreme. His only response to the storm is to "listen," even though listening makes his heart break.
| And kneeled and made the cheerless grate |
Porphyria, on the other hand, has more agency and activity than the speaker can handle – she's able to make the fireplace "blaze up," apparently without even lighting a match! She's the opposite of passive.
| And last, she sat down by my side |
The speaker can't even be bothered to answer Porphyria when she calls to him. And he doesn't even say, "I didn't answer" – he just notes, "no voice replied."
| She put my arm about her waist, (16) |
The speaker is so passive and apathetic that he just lets Porphyria move his arms around like a doll.
| I propped her head up as before, |
By the second half of the poem, the tables have turned: now Porphyria is the passive one (because she's dead), and the speaker moves her body around as though she were a doll.
| The smiling rosy little head, |
The speaker refers to Porphyria just as a "head" – an object, something that can't have a "will" of its own at all.