Wright’s Anna Karenina takes liberties by inventing a picnic that the screenplay by Tom Stoppard suggests is “a lovers’ idyll, by a stream on a warm day.” The picnic episode isn’t Tolstoy’s. As far as I know, there aren’t any picnics in his fiction or other works. 
However, there is a brief picnic episode in Bernard Rose’s 1997 Anna Karenina, and Wright and Stoppard adapted the idea. In Rose’s screenplay, Anna and Vronsky are amidst a tense discussion. Vronsky strongly suggests they leave Italy and return to St. Peterburg, and Anna unhappily acquiesces. Wright’s and Stoppard’s picnic is a passionate love scene. Stoppard says he wanted the narrative to be more “racy and sexier,” so two lovers are spread on the grass, eager to make love with no intention of moving on before they do.
This is Stoppard’s dialogue, which on the printed page is romantic fluff.
Anna: You love me.
Vronsky: Yes.
Anna: Only me.
Vronsky: No.
Anna: Apart from Frou-Frou.
Vronsky: Yes.
Anna: But me more than your horse?
Vronsky: Yes.
Anna: Are you happy?
Vronsky: Yes.
Anna: And you love me?
Vronsky: Yes.
Anna: How much?
Vronsky: This much.
Anna: This much.
Vronsky: Yes.
Anna: This much?
Vronsky: Yes.
Anna: This much?
Vronsky: Yes.
Anna: This much? And this much? And this much?
Vronsky: Yes.
Racy? Suggestive? Sexy? It plays better than it sounds.
The food and wine are somewhere out of reach.
Featured Image: Keira Knightley as Anna Karenina and Aaron Taylor-Johnson as Count Alexei Vronsky
See Leo Tolstoy. Anna Karenina: A Novel (1877). Translated by Constance Garnett. London Heinemann, 1901; Joe Wright. Anna Karenina (2012). The screenplay by Tom Stoppard is based on Leo Tolstoy’s novel; Tom Stoppard. Anna Karenina: The screenplay. New York: Vintage, 2012; Bernard Rose. Anna Karenina (1997). The screenplay by Bernard Rose is based on Tolstoy’s novel (1877