It's about Dickinson's inspiration and poetry. She opened every door of herself to find inspiration, and resisted the common literature world like shore against billows with roars and breakers.
Not knowing when the Dawn will come,
I open every Door,
Or has it Feathers, like a Bird,
Or Billows, like a Shore－
I open every Door,
Or has it Feathers, like a Bird,
Or Billows, like a Shore－
(F.1647/J.1619)
[1] dawn:: the beginning or rise of an idea, inspiration. To dawn is "to begin to be understood, felt, or perceived" (OED v. 4).
[2] Door:: way of communication.
[3] Feathers:: ideas that fly freely and are hard to catch. Feathers hints at feather pens. Feather also means "the foamy crest of a wave" (OED 11c) to link the following shore and billows. Bird:: an exceptionally smart person.
[4] Billows:: great waves of inspiration. Shore:: a land against billows that causes breakers.