What is a shorter poem that expresses an emotional state in a single, unified impression called?

A shorter poem that expresses an emotional state in a single, unified impression is known as lyric verse. This form of poetry is characterized by its focus on personal feelings and thoughts, often evoking a strong emotional response from the reader. Lyric poems typically do not tell a story or follow a narrative structure; instead, they are concerned with creating a vivid emotional experience and capturing a moment or feeling in a succinct manner.

Other poetic forms, such as sonnets, ballads, and elegies, have specific structures or thematic focuses that distinguish them from lyric verse. Sonnet, for example, usually adheres to a strict rhyme scheme and is often used to explore themes of love or nature over a longer format. Ballads generally tell a narrative story and often incorporate dialogue and character interactions, while elegies are mournful lyrics specifically focused on loss or lamentation. Thus, lyric verse stands out due to its emphasis on emotional expression in a concise form.