I think part of it comes from a misreading of Orr's argument (he is, after all, a lawyer during the day).
Here's Orr's opening paragraph:
"You are living in a world created by Elizabeth Bishop. Granted, our culture owes its shape to plenty of other forces — Hollywood, Microsoft, Rachael Ray — but nothing matches the impact of a great artist, and in the second half of the 20th century, no American artist in any medium was greater than Bishop (1911-79). That she worked in one of our country's least popular fields, poetry, doesn't matter. That she was a woman doesn't matter. That she was gay doesn't matter. That she was an alcoholic, an expatriate and essentially an orphan — none of this matters. What matters is that she left behind a body of work that teaches us, as Italo Calvino once said of literature generally, "a method subtle and flexible enough to be the same thing as an absence of any method whatever." The publication of "Edgar Allan Poe & the Juke-Box," which gathers for the first time Bishop's unpublished material, isn't just a significant event in our poetry; it's part of a continuing alteration in the scale of American life."
These are indeed big claims. But note that Orr goes on to define this sea-change - which Bishop allegedly has produced - in Bishopian terms. In other words, the review (like a poem, or a good tractate) "does what it says". Bishop's changed our world? She's changed my world. I'll show you how - in the very way I write this essay.
Orr hedges & qualifies the claims of the first paragraph throughout the rest of the review. The change-of-scale engineered by Bishop is one toward modesty and exactitude. It may not be noticed, proclaimed, or even noticeable. It's hidden, refined, buried, shaped - like the poems themselves. Yet the egocentric circus-wizards of 20th-century poetic melodrama are no longer holding sway.
(Re-reading the review, I was struck by the prevalence of the crystallography analogy, which I've often noted in Mandelstam. "Poets, envy the crystallographers!" and "Poetry : beneath its modest exterior lies an interior of terrifying density.")
Jonathan quotes this poem as a kind of evidence for his frustration with Orr's "invisible sea-change" argument:
The tumult in the heart
keeps asking questions.
And then it stops and undertakes to answer
in the same tone of voice.
No one could tell the difference.
Uninnocent, these conversations start,
and then engage the senses,
only half-meaning to.
And then there is no choice,
and then there is no sense;
until a name
and all its connotations are the same.
This is a poem about poetry. Note the overlapping rhyme scheme, as if the 2nd stanza were folded over the first : and the break in the rhyme in the 2nd stanza's 3rd line : & how this break echoes the logic of the line itself. That is, the "uninnocent" aesthetic echoing of an advancing poetic "conversation" has an inertial impetus of its own - the way conversations have an uncontrollable waywardness. And the poet partly resists this loss of control : "half-meaning to", she breaks the rhyme scheme.
As the 2nd stanza's rhyming inexorably advances, however, the poet (or lover, or lunatic) continues to lose control, to go toward chaos (no choice - no sense)... until, magically, a poem resolves itself : represented in this poem by the sudden turn of the final couplet, the "marriage" of the end-rhyme, and, additionally, the mirroring of that rhyme in its meaning. The name and all its others & otherness (its connotations) merge : "name" achieves "same" - union, coherence, synthesis (overturning the previous broken rhyme).
This is like a miniature plot reversal in a comedy.
Again, look at what the 1st stanza is saying : the hidden tumult in the heart begins to answer its own questions in the "same tone of voice", and "No one could tell the difference". This is exactly what the poem does, by moving to the 2nd stanza in an echoing rhyme scheme ("same tone of voice" - "no difference"). It's as if this hidden reflexivity - this mirroring process of art, which is interior, which no one notices - propels the poet toward a dramatic crisis, which only the counter-turn of the closing reversal can resolve.
All hidden, disguised, modest - a crystal hidden in a gray stone.
The poem opens with an echo of Yeats (the "tumult in the heart" : poetry as a quarrel with ourselves) and closes with an echo of Shakespeare (the resolution in the "name"):
The lunatic, the lover, and the poet
Are of imagination all compact.
One sees more devils than vast hell can hold,
That is the madman. The lover, all as frantic,
Sees Helen's beauty in a brow of Egypt.
The poet's eye, in a fine frenzy rolling,
Doth glance from heaven to earth, from earth to heaven;
And as imagination bodies forth
The forms of things unknown, the poet's pen
Turns them to shapes, and gives to airy nothing
A local habitation and a name.
(A Midsummer Night's Dream, 5.1.7-17.)
Addendum : Orr is not so much focusing on Bishop's effect on the shifting prestige rankings within poetry criticism, or within poetry subculture itself : he's talking, more radically, about an effect on the scale of culture-at-large.
That is, Bishop's style - of modesty, restraint, irony, precision - represents a foregrounding or magnification of certain qualities peculiar to poetry per se, as an art form amidst other arts and human activities. Her work embodies - crystallizes - these specific attributes.
And it is the subterranean, occulted impact of such "pure poetry" - as exemplified in the poem I just unpacked - which Orr is identifying and "magnifying" in turn.