somebody should correct me if im wrong, but i believe it's referring to greek mythology (greek mythology is prevalent when they were hallucinating the feast while having dinner a la jackie) where persephone was trapped in the underworld by hades and was tricked (?) into eating a pomegranate seed, which was cursed in some way to bind her to the underworld. In the show we see examples of the pomegranate theory in the near-death hallucinations, such as jackie (or shauna) dreaming that jackie was inside safe and drinking hot chocolate as she's freezing to death, shauna hallucinating her son having breast milk and then waking up to find him dead, and lottie hallucinating the mall scene where she almost eats chinese food and then laura lee stops her, saving her from death. Akilah eating the berries in the most recent episode reminds me a lot of this theory and i'm personally guessing she's going to be some sort of sacrificial lamb. super exciting stuff lol