Galaxy Fold: Why there is a slim film on device's main screen?

The protective layer is a part of the display module that reduces the external impact on the main display.

Precautions to be taken :-

•  Do not remove the layer. If you remove the layer, main screen will be damaged.

• Do not attach any adhesives such as protectors or stickers. The protective layer may be detached from the Main screen when you remove the adhesives.