What is the theme in A Narrow Fellow in the Grass by Emily Dickinson?

"A Narrow Fellow in the Grass" is built around the contrast between what appears to be and what is. Dickinson wrote several "riddle" type poems, where she uses an extended metaphor to compare her subject to something, without coming right out and telling the reader what she is describing. Each stanza offers "clues" in the form of imagery, vivid word pictures such as the "spotted shaft" that divides the grass "as a comb."