When an author's style consumes his or her characters

In one of the most fluid passages in Henry James's "The Ambassadors," James gives us the back story on two newly introduced characters (half-way through the novel) - Chad Newsome's mysterious beloved(s): Mme and Mlle (Jeanne) de Vionnet: through weird coincidence that typically takes James several page to unravel, the protagonist's (Strether's) guide/companion, Miss Gostrey, when to boarding school with the young Mme di Vionnet - you figure the chances, though it does seem to be a small and insular social set - and she fills Stether, and thereby us, in on the character and background of Mme de V., married to a brute, but one doesn't divorce, so they just live apart. It strikes me that James rarely does give back story - he lets almost the entire novel unfold, rather, through his strained and meticulous dialogue and through long passages in which he tells us what the protagonist is thinking: a violation of one of the cardinal rules of fiction writing, show don't tell, but in a violation so extreme that the rule-breaking becomes a new possibility in and of itself: a style unique to James and his sensibility, and I think probably never emulated (Cynthia Ozick maybe an occasional exception - though not an entirely successful one, in my opinion). As we get to know more about Mme de V., James careful sets her well-furnished Second Empire apartment up as a part of a triad: there's the old fashioned and conventional world of Connecticut, that Strether has left behind; the Bohemian world of Paris, to which he is inevitably drawn and which has seemingly won over his quarry, Chad Newsome; and there's now the wealth of Old France/Europe, before which he feels inevitably judged and found wanting (I don't know why - I'd say screw all that with the counts and their collections and lineage and class and race snobbery). In one of the many strange and strained dialogues in the novel, Strether discusses Jeanne de V with Mme de V and we learn, after much feinting and parrying, that she is not engaged to Chad - though why is not clear. He knows it would be bad for her to bring her back to the U.S.? He knows it wouldn't? who knows? There are intimations that he, Chad, may actually be in love with the mother (who's only in late 30s and very attractive), and also suggestions that Strether is falling for him. By the end of their conversation, they have reached some kind of agreement - and they are talking about who is going to "save" whom. Honestly, at times the subtlety of this dialogue is is so extreme that the meaning just vanishes like smoke. Oh well - in a James novel, every character talks (and thinks) expansively like James, just as in a DeLillo (or Carver) story every character is pithy. An author's style that consumes, or assumes, his or her characters can easily become a mannerism or even a self-parody.