Pipeline description is unclear

[jwbth]

I was passing by, and when trying to make sense of the pipeline, I'm stuck on the first step:

Query: cast of Oppenheimer Christopher Nolan film

How is the query extracted from the message in natural language? Does this involve some NLP standard tasks for text mining or even another message to LLM? In any case, it seems that query is not the actual first step as it is stated.