Sometimes, revising means polishing existing sentences and paragraphs, but sometimes it means reimagining whole scenes. You can get so absorbed in perfecting your sentences that you forget to check how the passage reads. It’s a forest/trees thing. Forget for a moment that you’re the writer, and read that revised page as though you’re a bookstore customer sampling the book, trying to decide whether or not to buy it. Does it compel you to keep reading? Did you include every phrase that was necessary to keep the story moving, and leave out everything else?