When taking pictures or videos of the LS3 screen the display is only partly shown

This happens in very bright light (sun light) due to the refresh rate of the OLED display. This rate is 100Hz (the display is refreshed 100 times per second). Cameras will only capture a part of this refresh whenever the shutter speed is greater than 1/100th of a second.
This effect can be avoided by either shielding the display from bright light, or manually adjusting the shutter speed to anything below 1/100th.