From a wikipedia article on foreshadowing.
A similar device is the flashforward (also known as prolepsis). However, foreshadowing only hints at a possible outcome within the confinement of a narrative. A flashforward is a scene that takes the narrative forward in time from the current point of the story.
By analogy to foreshadowing, the literary critic Gary Morson described its opposite, sideshadowing.[7] Found notably in the epic novels of Leo Tolstoy and Fyodor Dostoyevsky, it is the practice of including scenes that turn out to have no relevance to the plot. This, according to Morson, increases the verisimilitude of the fiction because the audience knows that in real life, unlike in novels, most events are in fact inconsequential. This "sense of structurelessness" invites the audience to "interpret and question the events that actually do come to pass".
Sideshadowing goes against the "If it doesn't move the plot forward, delete it." Although, it might explain why the Russian novels are so long.
