First, ask yourself - where do I know this room from. If you don't know this room, then you probably never will get this joke.
Once you've identified the room, you could ask yourself - who is the person associated with this room. If you don't know who's associated with this room, then you probably never will get this joke.
Once you've identified the person, you *should* be able to determine who Hunter is. And if you know who Hunter is, you'll know why this joke is funny.
If you aren't into politics, this is going to sail right by you.