How does Sara Teasdale use imagery in There Will Come Soft Rains?

Lines 3 and 4 introduce more elements of nature in the form of frogs, pools, and plum trees. The frogs are depicted "singing at night" to show their nonchalance toward the world around them. Line 5 also contains a foreshadowing image, as the robins are wearing "their feathery fire." While the reddish orange color of robins' breasts may resemble the color of fire, there is likely more to the word choice here than an attempt to match hues. Fire is a part of war.