Like many other Emily Dickinson's poems, "It dropped so low — in my Regard" wasn't published until after her death. Like many other of her poems, "It dropped so low — in my Regard" is enigmatic, unconventional, and eccentric, and it defies analysis and definitive interpretation.
It dropped so low — in my Regard —
I heard it hit the Ground —
And go to pieces on the Stones
At bottom of my Mind —
"It," whatever "it" is—and only the speaker knows what "it" is—is something that she held in high regard, but "Fate," or chance (or the inevitability of growth and discovery, or perhaps even self-discovery) causes "it" to be brought into sharp focus in the speaker's mind, where it proves to be much more insubstantial and significantly less worthy of esteem than she had previously believed.
On closer examination, "it" isn't really as precious, meaningful, or important as the speaker once thought it was, and "it" crashes to the stones on the ground—falls to the depths of utter disregard at the "bottom of my Mind"—like a piece of pottery, and breaks into pieces.
Yet blamed the Fate that flung it — less
Than I denounced Myself,
For entertaining Plated Wares
Upon my Silver Shelf —
Rather than blame herself for her own mistaken or misguided estimation of the worth of whatever "it" is, the speaker chooses to blame "Fate" for, in effect, throwing it into her face so she can't ignore it, which she might have done had not "Fate" intervened.
Nevertheless, the speaker scolds herself for being misled by false appearances ("Plated Wares"). She shouldn't have been so easily taken in or become so readily enamored of the silver-plated, artificially enhanced, deceptively presented object. She should have known that the silver-plated "it" shouldn't be held in the same regard or esteem as the pure silver or sterling silver objects on her "Silver Shelf."
There seems to be a mixed metaphor in the poem. The speaker first mentions that "it" falls to the ground and goes to pieces on the stones, like pottery or crockery, or even glass, but then she changes the frame of reference to silver, either plated or real silver, which doesn't shatter or go to pieces when it falls on the ground or on stones. The changing imagery of whatever "it" is simply adds to the depth and mystery of the poem and makes a definitive analysis even more elusive.