Formalism developed in Russia as a reaction to the then prevalent literary criticism that associated literature with its era's social and political realities. For example, you might think of early twentieth century (1900s) literary criticism of Dickens' work. It was critically analyzed for its social commentary and exposé. Charlotte Brontë was routinely critically analyzed in terms of social roles. In fact, these novels, and other similar ones, are still dominantly viewed through these lenses today.
Formalists sought to separate works of literature from their socio-political exposé and message and critically analyze them in terms of literary merit; this in English was called "literariness." Formalists sought to make a scientific study of literature that discovered the order and form in literary works. Influenced by the then still new field of Linguistics, Formalists sought to find this order and form within the words of the text and to discover universal form that was common to all literature. How was this to be done? This was to be done through the language and literariness of the text. Therefore the words of the text, also called the narrative content, create the form, hold the form, generate the order, and are the form of a literary work.
Literariness is, according to formalism, shown in features and devices. Note that, according to Vince Brewton, Ph.D., of the University of North Alabama, it was New Criticism--which came after the Soviet's discredited Formalism for having no political awareness--that emphasized the devices of irony, paradox, ambiguity and metaphor (plus others); these were not the emphasis for Formalists. A dominant function in Formalism is "defamiliarization," which indicates the quality literariness bestows on everyday minutia once an author brings it to light under a telescope of intent and examination to reveal the minutia in new and revelatory ways.
A few other functions are fabula (causal chronology); self-consciousness (how deeply the narrative address the reader, think Fielding versus Hemingway), and communicativeness (how thoroughly the narrative exposes the deep level story; different from the surface level discourse or plot) (David Bordwell Ph.D., University of Wisconsin–Madison). Some devices of concern to Formalists are: motifs; rhetorical, poetic or literary devices (like diction); literary techniques (like symbolism) (Brewton). It is this highly particularized aim and mode of criticism that equates form with narrative content, even including story (fabula) and plot (syuzhet), so that it is correct to say that form is the narrative content under a formalist critic's lens.
In Emma, a formalist would look for the fabula--which is: spoiled rich kid torments others then learns her lesson from the love of her life--and the differentiated plot (narratologists call "plot" the discourse at the surface level of the narrative) action that makes Emma's syuzhet (discourse) unique, even while the fabula is a universal, deep level, story. Formalists would also look for rhetorical devices that give Emma literariness and defamiliarize significant elements, such as the outing to Box Hill or the strawberry picking. A significant rhetorical device is the verbal irony Austen imbues her characters' dialogue with.