Thank you for your support of Xiaomi products. The phone undergoes strict professional inspection before leaving the factory, so you can use it with confidence. If you experience ghosting or faint traces of text or images while sliding through the interface on your Xiaomi 15 Ultra, this is a common characteristic of OLED displays and is seen as a normal behavior. Ghosting occurs when a faint afterimage from previously displayed content lingers for a short period. This is due to how OLED pixels are controlled and how they fade in and out when changing images quickly. Ghosting will generally not affect the overall functionality of the device or your daily usage.
You can also manually set the refresh rate to 120Hz, or adjust the font to a finer setting to alleviate this phenomenon.