Emily Dickinson's poem beginning with the line "It dropped so low -- in my Regard" is open to a wide variety of interpretations.
One thing we can note is that she juxtaposes concrete objects with abstract concepts. We see this juxtaposition in the very first stanza when she opens with something dropping so low that it hits the ground and shatters into a million pieces "on the Stones." Only concrete objects can hit the ground and shatter on stones. Yet, the reader is left trying to answer the question, what exactly fell? And the answer lies in the fact that her next line refers to an abstract concept rather than a concrete object, showing us the juxtaposition between the concrete and the abstract. Her final line in the first stanza refers to the "bottom of my mind," and a mind, or a person's thoughts, is an abstract concept not a concrete object. Therefore, whatever fell only fell in her mind, not in reality.
In the second stanza, she begins speaking about her reaction to the unknown thing that has fallen in her mind. She "blamed" fate for it having fallen. She further says she blamed fate less than she "denounced [herself]." To denounce is to censure, meaning to reprimand or show disapproval; therefore, she is saying that she blamed fate rather than blamed or censured herself. Yet, since she is juxtaposing blaming fate with blaming and censuring herself, the reader can conclude she thinks blaming and censuring herself is really the more appropriate response.
The reader is next left to ask, what is it about this unnamed fallen object that makes her feel she should censure herself? The answer lies in the next two lines: "For entertaining Plated Wares / Upon My Silver Shelf--." Here, the word "Plated" refers to gold platting; the word "Wares" refers to any items, goods, or services that can be bought; the verb "entertain" is probably best understood by its obsolete definitions, which are to receive, as in receiving company, or to look after; and the image "silver shelf" simply refers to a literal shelf made of silver. Hence, all in all, she is saying that she blamed fate rather than blamed and censured herself for receiving and looking after some gold-plated object on her silver shelf. But what does that mean exactly?
Something else fascinating in these lines is the juxtaposition of gold in the word "Plated" with "Silver." Silver is far less precious than gold; hence, whatever object she had displayed on her shelf that fell and shattered was far more valuable and costly than the shelf she put it on. In other words, she is calling herself inferior for entertaining on an inferior shelf whatever precious item she had that shattered. One might assume that the object was a dream or ambition; therefore, she is saying that she is far too inferior to have entertained such a dream or ambition, and, of course, it has now shattered into a thousand pieces.
All in all, the poem is about loss. The speaker has just had to give up on something, like a dream or an ambition, because it has just shattered, and she prefers to blame fate for it having shattered than to blame herself for being so foolish as to entertain such a notion when she is clearly unworthy; yet, she clearly realizes she is truly the one to blame.