I’ve read that they may “befriend” a potential meal for months..treating him with kindness even offering a woman from their tribe. The idea is to get the victim so relaxed that he begins to accept the idea that he has become a part of the tribe. Then one night, the sound of drums and chanting and the tribe comes crashing into where the victim is sleeping. The idea is to kill the victim at the height of his surprise and terror as this amps up the magic transferred as the victim is consumed by the tribe!
There was evil in those grins as photographed. You can detect that they had “plans” for the young Rockefeller!
I heard that this is why sharks will circle in the water first, showing their fins. They like to scare the 'carp' out of their human prey first. A little preparation goes a long way.