Even a stopped clock is right twice a day. This so-called "dancing shrimp" sounds like a stupid, barbaric practice that should have led to the restaurant's closing. Getting one's jollies from the suffering of any creature, no matter how seemingly inferior, is sadistic and inhuman. It is in fact proof that the creature is not inferior to its torturer.
Like twisting the eyes of lobsters when holding races on the kitchen floor while they were waiting for their turn in the pot!