Complex sentence: The DxO ONE has a small OLED-powered touchscreen on the back, which can be used to switch between still and video recording modes when it is not attached to a mobile device, and also displays the device's current status and battery charge.
Split into simpler sentences: The DxO ONE has a small OLED-powered touchscreen on the back, for use switching between still and video recording modes when it is not attached to a mobile device. The screen also displays the device's current status and battery charge.