I think its more the way the engine handles artificial light hitting the skin, like light from lamps fires and other such non-sun sources. It doesnt seem to recognise the body itself as a shadow casting body so all surfaces thats turned to the lightsource gets hit no matter if theres a hat or a puffy chin in the way. This makes it look unnatural cause we arent used to those features lighting irl.



As can be seen here the light does not care about alphis hair, hitting the cheeks and puffs his eyes making him look like a insomnic corpse. Very unsettling effect on some races. Lalafells are less affected by this due to their flat featureless faces. This is also why the lower lip often lights unnaturally on some races.