The film does seem to indulge in a bit of whimsical “magical realism” (where fantasy elements seem to be a natural part of what’s otherwise a realist setting). Often times, these supernatural moments appear to manifest in Keaton’s mind, not in reality, but there are moments like the end where they could very well be happening. Rather than take things too literally, a better question would be, why does the film even use these supernatural moments at all? There’s been much debate over this, but most believe it’s metaphorical, equating artistic endeavors with magical accomplishments.