The Portrait of a Lady: time

After about 300 pages of foreshadowing... bang! there comes the news of Isabel's marriage to Gilbert Osmond. We all know what to expect, but it still comes as a surprise, even a shock, because of its suddenness, because of the feeling that it's all said and done, unchangeable, irreversible. How does Henry James achieve that? By taking a leap in time, by skipping the "necessary" scenes; by throwing us right in the middle of a scene that makes us as shocked as everyone else in the novel that knows Isabel. When Isabel communicates the news to other characters, she does so also to the readers. At the same time, whereas George Eliot focuses on the thoughts of Dorothea and Gwendolen before their marriages to Casaubon and Grandcourt respectively, to delve into their aspirations and motivations, to understand why they do what they do, Henry James doesn't show us what leads up to that final yes. Instead, he's interested in how Isabel reacts to people's reactions and defends her own decision, before others and in her own mind. There we have her reasons, but they are defences, justifications.
Then he makes another jump. George Eliot goes slowly, skipping nothing. We witness Dorothea and Gwendolen contemplate the proposals in their minds and say yes, we walk with them as they innocently enter their miserable marriages, we're with them after the wedding, when their eyes start to be opened. James gives us none of that. I'm on chapter 38 at the moment, and Osmond doesn't do anything specific that proves him a monster, but there are hints, lots of hints, here and there. Again there's a feeling that we're thrown into the middle of something, that we're late, that we miss out on details and don't quite know what's going on except a feeling that it isn't good. The uncertainty is suggestive. Usually, if my knowledge of 19th century novels is worth anything, when there is a jump in time, there must be a paragraph or 2 summarising the general incidents. In The Portrait of a Lady, there is nothing. It makes us not know what to expect, it causes a feeling of dread, terror.
Regarding Isabel, there is a sense of incompleteness in the character. A vagueness, abstractness. Not fully fleshed out, if readers judge Isabel by the standards by which we praise Anna Karenina or Emma Bovary. But it's this quality of vagueness that invites us to participate in the reading, drawing, understanding of Isabel, that makes us involved, that creates in us the urge to figure her out, label her, shape her, put her into some neat box, like other characters do. It may be frustrating, it may cause a faint sense of dissatisfaction, but somehow it's fascinating. The other characters are spectators, and so are we.
Let's see what she's going to do.