Your metaphor is clearly better; grandma performing HEAD requests on fish (a URI) is priceless.
However, if granny were in a hurry, she may ask the waiter "Will my order be up soon?" to which the waiter would, after checking with the kitchen and receiving a 304 Not Modified on the still raw fish resource, he could decide to then 307 to some free breadsticks resource.
Of course, after lunch, dear granny will eventually receive a 402. Let's hope she has money today, or she may end up 401'ed and have to start washing dishes.
In fairness, that also describes FTP, POP3, and DNS.
Edit: and LDAP, and Redis, and medical PACS datastores, and RDBMS in all their multifaceted splendour... a freakish amount of programming boils down to CRUD.
Edit 2: and Gopher. I feel a little sad for forgetting about Gopher.