It's because women don't usually take off a lot in the bed scenes of Korean dramas.
Also, the hand movements of the actors in the first picture are very awkward.
It's not as hot and turbulent as the bed scenes in American dramas, so it doesn't feel real.
Do you feel like you just have to act?
And most of the airwaves bed scenes are just the names of the bed scenes, just hugging and kissing haha