The shot was made in March at a Taco Bell in Ridgecrest, 100 miles north of Los Angeles.
Taco Bell Products Inc. says the shells were provided for workers to practice making its new Cool Ranch tacos and were thrown out without being sold.
The Irvine-based company says the photograph was taken for a contest showing employees enjoying their first bite of the product. It wasn't submitted, but a worker posted it to a Facebook page - which violates company policy.
Taco Bell says the worker also violated food handling procedures.
The company says the licker has been suspended and will be fired, while the photographer no longer works at the restaurant.