What is the poet's view of language and metaphor in the poem "You Begin" by Margaret Atwood?

In this well-known poem, Canadian poet Margaret Atwood
contemplates the development of language and how metaphor helps human beings deal with
increasingly abstract concepts. The critical lines from the
poem follow:

The word hand floats
above your hand
like a small cloud over a lake.
The word
hand anchors
your hand to this table,
your hand
is a warm stone
I hold between two words.

Here is
the core of her semiotic argument. When explaining the dynamic relationship of
signified - the hand itself - and the
signifier - the word hand  - the
speaker first resorts to simile (the poor man's metaphor). Thus, "the word hand
floats...like a small cloud" - as if to say, like an insignificant, passing thing.
However, in the next line, the poet invokes the almost magical power of metaphor to
create our understanding of reality. No longer is the word hand
floating, it is anchoring the thing itself to its sign, though the reader perceives that
the two are tethered together - they are not one and the same thing. But in the last two
lines, language performs its semiotic magic act: In a wondrous exchange of meaning, the
physical hand becomes a metaphor - "a warm stone" - while simultaneously retaining its
status as 'word'. Thus signifier and signified, while remaining as they have been,
become one, and language is
born.