Core Viewpoint - Mobile manufacturers are increasingly focusing on the materials used for phone backs, as different materials not only provide varying tactile experiences but also allow for bolder designs [1][3]. Material Analysis - **Plastic Back**: Offers high practicality with low production costs, durability, and does not interfere with signal reception, making it a common choice. However, it lacks aesthetic appeal, leading to its relegation to entry-level models [4][6]. - **Glass Back**: Since the introduction of the iPhone 4, glass has become a mainstream choice for flagship phones due to its excellent moldability, electromagnetic permeability, and superior tactile feel compared to plastic and metal. Innovations like microcrystalline glass have emerged, combining the benefits of glass and ceramics [7][9][11]. - **Ceramic and Leather**: Ceramic backs provide a premium feel but are costly and fragile, limiting their use. Leather backs, while initially seen as a novelty, have gained traction for their aesthetic and functional qualities, including durability and heat resistance [14][16]. - **Fiberglass**: Recently introduced by Huawei, fiberglass backs offer a lightweight, durable, and visually appealing alternative, effectively addressing the shortcomings of other materials and allowing for innovative designs [21][23]. Evolution of Materials - The evolution of mobile phone materials reflects advancements in technology and changes in design philosophy, transitioning from plastic and metal to glass, ceramics, and fiberglass. This shift indicates a pursuit of balance between functionality, aesthetics, and user experience [24][26].

Group 1 - The core idea of the article revolves around Lei Jun's entrepreneurial journey in the internet sector, emphasizing his deep reflections on the internet, learning from various companies, and the evolution of Xiaomi [1][2] - Lei Jun views the internet primarily as a tool, predicting that all companies will eventually become internet companies. He believes that the internet represents a revolutionary change in mindset, focusing on open collaboration, machine-driven profits, word-of-mouth marketing, efficient management, service provision, and rapid growth [1][2][19] - Before founding Xiaomi, Lei Jun drew inspiration from companies like Tongrentang, Haidilao, Walmart, and Costco, focusing on quality products, exceptional service, low-margin high-efficiency operations, and community engagement through Xiaomi's platform [1][2][28] Group 2 - Lei Jun's cautious nature led to missed opportunities during the early internet boom at Kingsoft. His departure from Kingsoft marked a turning point, allowing him to regain confidence and experience before launching Xiaomi at the age of 40 with a commitment to innovation [2][3] - The external perception of Lei Jun and Xiaomi has been mixed, with initial praise for Xiaomi's internet model, followed by skepticism as competitors like OPPO and VIVO emerged. Lei Jun maintains that Xiaomi's growth phase is normal and that acceptance of its model may take up to 15 years [2][3] - Despite challenges such as low yield rates for products like Xiaomi MIX, Lei Jun remains committed to technological innovation and cost-based pricing, reflecting Xiaomi's core values [2][3]