The Brits have a saying: “it does what it says on the tin.” It is, of course, an observation of the obvious: The thing inside the box performs or functions as advertised. It’s an observation that clearly applies to Ceviche House (2415 San Diego Ave.) in Old Town. It is, indeed, a house where ceviche is served. Ceviche and related forms of elevated, raw and fish-based dishes is what they offer. But in that British saying, there’s also some irony, a touch of sarcasm and a serious question.