Eliot's narrator veers from cloying to caustic so abruptly that you might need Dramamine. For example, she goes from describing Mrs. Kimble as having "a double dignity, with which her diameter was in direct proportion" (1.11.3)—i.e., she's fat—to praising Nancy as giving "the same idea of perfect unvarying neatness as the body of a little bird" (1.11.9). Elsewhere, the narrator has a man describe his wife as "too fat to overtake [a child]: she could only sit and grunt like an alarmed sow" (1.13.47). But Eppie! Eppie is just the cutest little thing. When we meet her, she "toddles" twice in one paragraph and then is described as "gurgling […] like a new-hatched gosling" (1.12.3.). It's even worse when she grows up: she skips about and calls Silas her "little old daddy" (1.16.20).
What these snarky and sentimental descriptions have in common is a keen eye for detail. Eliot's narrator spends a lot of time describing not only people's appearances but their personalities through direct narration, dialogue, and action. Above all, she an observant watcher, giving the impression that she's actually lived among this community.
There's a telling line when she narrates Godfrey's last look at dead Molly: "at the end of sixteen years every line in the worn face was present to him when he told the full story of this night" (1.13.38). The implication here is that Godfrey told the story to the narrator, or at least told it to someone who told it to her. This kind of gossipy writing makes the narrator as much a part of village life as any of the characters she's observing.