it is meant to be symbolic, and makes a point, both in the book and in the Disney version, which changes the words and has different imagery, such as luring them back to their lair as opposed to eating them on the beach.
However it still depicts a simple scene from nature. Walruses eat oysters among other smaller sea creature. Sharks eat fish spiders eat flies, birds eat worms, and humans eat just about anything and everything. The world is predatory. And maybe that is the message. A cautionary tale.
Maybe Alice is an oyster, an innocent with no idea she can be lured into a predators lair and eaten. Alice is a lot like Red Riding Hood about to be eaten by the wolf. Which itself is a metaphor for a young girl just got her first period, hence the red, and the predators who will come sniffing after her. My what a big cock you have. All the better to fuck you with.
Or maybe they really are gods, as Matt Damon says, Jesus, Buddha, Ganesh, and are after souls. Maybe gods eat souls.
A warning not to follow them.
