Chapter card

A chapter card, eyecatch, or bumper is (most commonly) an image or (uncommonly) short animation sequence used to designate a transition between chapters or acts. (Different from a simple scene transition.) Usually used to give the reader a moment to stew over the end of an important scene and anticipate the next.

For games that don’t have chapters, it may be used instead to indicate a player has transitioned from the common route to a specific character’s route. When used to indicate a route change, its purpose is to inform the reader which route they’re on and in that case almost always include a picture of the route’s character or something related to the character.

A note on the terms: “Chapter card” is probably the most accurate way to refer to it if its a still image with some sort of indication of the chapter or route on it. “Eyecatch” is probably the term you’d want to use for either a still image or animation sequence if there is no designation of a specific chapter/route. (It comes from the Japanese aikyatchi, which are the sequences around a commercial break which may or may not be animated.) “Bumper” is the Western term for a generally animated sequence that surrounds a commercial break.