The "creative thrust" mentioned in the last post has to do with the relative intimacies of one's writing. These may change from time to time - based on the writer's growth and on his/her intentions toward the text and the reader. For the most part, these intimacies can be summed up this way:

• style - here the writer selects a mode of prose writing that fits either his/her personality, the tone of the era in which the story takes place, or a mode of writing currently in vogue. For instance, a romantic style might eloquently depict the natural world through narrative, or an almost poetic manner of depicting life and characters. Postmodern style then could be satiric and fragmented.
• tone - it's hard to separate style from tone sometimes, but you might say tone connotes mood. John Steinbeck's writing is to me strong on tone or mood, implying in much of his writing the mysteries of life. Postmodern tone could be cynical, apocalyptic, nihilistic. 
• voice - this is probably the most intimate nuance of prose writing. An accomplished writer will develop over time - and despite variations of tone and style - a manner of writing unique to the writer. Hemingway's voice is easily recognized, as distinct, say, from Ian McEwan's or James Joyce's.

A good writing partner will recognize these relative subtleties in one's writing, how one predominates, how they blend as distinctively into something as unique as one's signature. The partner won't monkey with these, nor ignore them - will in fact help this writerly "signature" virtually dictate everything else, from sentence lengths to story structure.

The writer's main problem is often one of big picture versus complementary details. With an eye on this big picture, the writer may omit details, or over-emphasize them. Conversely, a  writer preoccupied with style, voice, et. al., may allow the story to wander into blind alleys. An accomplished partner will note these and will strive to help the writer tweak them back into a consistent form.

"Forest or trees" syndrome is my term for the condition in which writers with skills not fully developed tend to write for themselves. The whole of editing and critique, then, is to make the writer more aware of all these technical elements on the reader. That's what the partner is: a first reader. It's been said that a writer will only depict through story some 20% of what he/she knows about these characters, the setting, this story. The writer's "focus group"," then is the writing partner: some elements may lead to the partner's confusion; some may enthrall, others may bore. Not that there's any right or wrong here - it's simply a learning process in which the writer slowly becomes aware of how the various elements of writing affect the reader's experience. Such awareness, then, adds a second edge to the writer's technical writing sword. The most coherent stories are those in which the writer's techniques clearly take the effect of these elements on the reader into account as he/she writes.

Finally this: I wrote last time that writing partners must have parity of skill set. If this isn't present, one will be preoccupied with bringing the other up to technical speed, and the manuscript won't improve. That, then, is the essence of critique, of writing partnerships - it's a mode of collaboration in which the manuscript will improve and in which those involved will grow, as they resolve these technical problems, in their understanding of and abilities with prose writing.