B-roll: cutaway shots of the product in use
Short clips of a person using the product, cut between takes. Pick the shots, the model and the count.
B-roll is the footage cut between the creator's lines: the product being picked up, opened, used, turned in the hand.
The B-roll step shows angle tiles (use it, hand hold, first use, unbox, over the shoulder, routine, slow rotate). For clothing they become putting it on, a detail close-up, a mirror check. Faces may appear but never look at the lens; the product is the subject.
Kling 3.0 is the default; Veo 3.1 Lite is the cheap option; Seedance 2.0 the cinematic one. Each has its own price and length ceiling, shown on the tile.
B-roll is made with the product photo as a reference the model composes around, not as an opening frame, so a shot never starts on a white studio photo and dissolves into a room.
The Assemble step can add cutaways by itself, filming what the adjacent line describes, on the model you chose here.