When it comes, the Landscape listens— Shadows—hold their breath—
Maybe you've had that feeling before of nature kind of standing still for any number of reasons. It's as if nature is listening to us and the rest of the world.
Here, the speaker senses the same sort of stillness that comes with that mysterious "Slant of light." The landscape listens and the shadows around it are still and figuratively "hold their breath" in line 14.
Notice all the dashes we have in these lines. Here, it sounds as if the dashes are acting like the staggered breath that the shadows appear to have. They're in between lines and within line 14 as well. Each time we see one we pause for a second, again similar to the way the shadows and landscape are listening and holding their breath. Check out "Sound Check" for more on this technique.
The personification of the landscape also serves to blend the speaker's inside and outside worlds. It's as if the landscape and the outside world are responding to the light in the same way the speaker is. The speaker is jarred and disturbed by the slant of light just like the landscape and shadows that "hold their breath."
The capitalization of "Landscape" and "Shadows" also gives the impression that we're dealing with proper nouns like people's names.
Notice that the mood here is also a bit different from what we've seen in the previous stanzas. There's a sort of anticipation here that's different from all the despair we've seen. So as much as the speaker may feel "oppressed" by the light, there's also something here that is somewhat alluring and mysterious.
When it goes, 'tis like the Distance On the look of Death—
It wouldn't be an Emily Dickinson poem without some sort of reference to death. And here, her speaker doesn't disappoint.
So when the light "goes" it kind of has a distant look similar perhaps to what death looks like: "on the look of Death."
The idea here is a bit puzzling, but if we imagine the "look of Death," we can kind of see what the speaker is driving at. Dead things and dead people do have a "distant" look, probably because they're dead. So the macabre imagery here adds to the mysterious quality of the slant of light.
We see the light's exit in the same sort of distant way we might see death. It's as if it's going off to some mysterious place us earthly folks can't fully see or understand. So it's therefore quite "distant" and again difficult to define.
Adding even more intrigue is that final dash. Since the poem doesn't end in a period and instead ends with this dash, we're left feeling as if the poem continues elsewhere. Perhaps it continues in the same place the "Slant of light" has gone off to.
So all the blending of that mysterious light with the speaker's "internal difference," leaves us with a sort of lingering wonder, which that final dash serves to emphasize.
By the end, we don't necessarily have any definitive answers in regard to the light or the speaker's internal conflict. But that's kind of the point. When these "internal differences" are illuminated by either nature or something else, we may feel enlightened for a moment, but we may also feel equally "oppressed" and at a loss for definition.