I'd suggest making it more than 10 lines of code. Similar to kids finding easter eggs -- you want a reasonable number of things out there to talk about. It sounds like you try to get there by keeping it simple, but I would posit that some people's brains may lock up on a single block of code and having it in context or more there gives them something else to look at. Our brains are very bad at having insights when focused on the thing you're trying to have an insight about.