Core Viewpoint - The article discusses the decision-making process behind the design choices for the Li Auto L9, particularly regarding the use of AD cameras for streaming rearview mirror functionality, emphasizing the trade-offs between technology and user experience [1][2][3]. Group 1: Technical Considerations - The 2022 Li Auto L9 utilizes a physical rearview mirror alongside a 21.4-inch screen for streaming, indicating a shift towards a more integrated display system [1]. - The AD camera has a limited field of view (FOV) of 60 degrees, which is insufficient compared to a 120-degree view that can capture more lanes, thus affecting user experience [2]. - The clarity of video is a concern, as AD cameras typically have lower resolutions (200-300 million pixels), while high-quality streaming mirrors require at least 800 million pixels for optimal performance [2]. Group 2: User Experience - Transitioning from a physical rearview mirror to a streaming version can cause dizziness if the FOV does not match human vision, which is why a 120-degree angle is preferred [2]. - The quality of images at night can suffer when using AD cameras, leading to yellowish tones and noise, which is not suitable for user-facing applications [2]. - The decision to not reuse AD cameras is based on the understanding that the needs of machines and users differ significantly, necessitating tailored solutions for each [3]. Group 3: Cost Implications - The choice to develop a new high-position brake light and an additional 800 million pixel camera incurs extra costs, which must be accepted by users as part of the product's value proposition [3].