"A narrow Fellow in the Grass” is so Emily Dickinson, it makes Emily Dickinson look like Sylvia Plath. Um, well, so maybe that doesn't make much sense, but the point is that this poem has Dickinson's trademarks all over it.
Without even reading a word, in fact, you can tell from the odd capitalization and the seemingly random use of dashes that this is Emily's work. Those idiosyncrasies in her writing style were originally edited out as her first publishers sought to "correct" her mistakes. Over time, though, scholars have come to appreciate the possibility that Dickinson was actually writing this way, you know, on purpose, and that folks were doing her poems a great disservice by trying to force them to follow conventional rules.
The use of the ballad form is pretty much the only rule that Dickinson ever sticks by, and even then she does so in her own, unique way (see "Form and Meter" for more on that). In the end, "A narrow Fellow in the Grass” is, like all of Dickinson's poems, entirely her own—small, yet incredibly dense, jammed with possibilities of interpretation that leave some readers tearing their hair out, and others frolicking down the seemingly-endless paths of her poetic intentions.