The black levels don’t match, the lighting doesn’t match, the part where the balloon joins the neck changes shot to shot. Clothing details like his collar change. The balloon itself is even replaced by a human in several shots seemingly because it’s too shiny for continuity. The Sora output has to be stabilized and cut out showing fluctuating edges and highlights because Sora doesn’t have an alpha channel and can’t actually composite anything, just mush images together.