The Xiaomi 15 Ultra is built with cutting-edge caulking glue technology, which is used to fill the gap between the middle frame and the screen. This process not only enhances the overall aesthetics of the device, providing a more refined front appearance, but it also improves the phone's waterproof capabilities. To ensure the best quality, the device undergoes a combination of fine automation and manual polishing to achieve a seamless finish.
However, due to the use of different materials for the screen, the filling glue, and the middle frame, there will be slight variations in the appearance of the glue line, particularly when viewed under natural light. This can sometimes create the illusion of a non-smooth glue line, overflow, or residual glue. Please note that this is a normal and expected result of the materials and manufacturing process, and is not a defect or quality issue. The function and waterproof performance of your device will not be affected in any way. Please rest assured to use it.