A slap to the face usually causes more emotional damage than physical. The face is what you consider “yourself” the most, your identity, so slapping it is emotionally an attack on your being more than on your body (compared to other body parts), so there’s humiliation attached to it.
This incident happened decade ago in Indian reality show named Dadagiri. The guy who slapped is pretty successful now with his TV acting career while the host and that women’s career is completely ruined.