Looking

A player within the look distance comes first. When none is close, the NPC looks at another NPC, then around at random, then back the way it was placed. Player NPCs and mobs do this for each player on their own screen; a model turns for everyone at once.

#Look At Players

Turns the NPC's head toward players within the look distance.

#Only When Seen

Ignores players who cannot see the NPC through blocks. On Folia, a player in another region than the NPC always counts as seen.

#Look At NPC

Another NPC to look at while no player is close, or Nearest NPC for the closest one within the look distance. The other NPC has to be in the same world.

#Look Around

Looks in a random direction around the way the NPC was placed, every few seconds, while no player is close. The sideways and up-and-down ranges are in degrees; 0 keeps that direction still.