Video backgrounds can add a dynamic and visually interesting element to a Facebook page. One unique idea for a video background is using flying triangles. These triangles can be in different colors, sizes, and speeds to create a mesmerizing and abstract effect. The video can also have a subtle animation of the triangles changing direction, rotating or overlapping each other, to create a sense of movement and depth. Using a video background with flying triangles can give a modern and tech-savvy feel to a Facebook page, making it stand out from the typical static image backgrounds.