Messages sent by the end user, (referred to as "transcripts" in the API requests) are currently available across a variety of domains, the primary ones being streaming, news, shopping, and restaurants, with new domains being added regularly.
The first query typically begins by looking for something specific ("I want to watch family guy") or a recommendation ("What's a good action movie with Tom Cruise").
Follow up queries can refine the result you were given. If you don't like a recommendation or want to refine it, you can. For example, if you were recommended "Mission Impossible: Ghost Protocol" you might respond, "Actually, anything but Mission Impossible". The context of "action", "movie", and "Tom Cruise" will be remembered, but will omit anything from the Mission Impossible franchise.
You can also ask for more details about a result. For example, if you are looking at a book recommendation, you might ask "Who wrote it?" or "How long is it?" For a restaurant, you might ask "Can I see the menu?" or "What kind of food do they have?"