I'm sure I just grabbed it randomly. For chimpmails and public club work I buy images from Canstockphoto to use a legit image as a starting point. It might even be in there (the stock photo houses have considerable overlap).
For what it's worth, my theme suggestions are rarely the literal suggestion (as in, "use this image") but examples of things that could fit with a theme concept. A type of brainstorming. I tend to think of themes, uh, thematically rather than representationally. In the case of that image I was suggesting Cairnival as a theme because you could used midway concepts, striped tenting, cheesy games, thrill rides, striped popcorn bags, food-on-a-stick, pennants, maybe steal some crossover ideas from circuses, and so on. I was thinking of making a "cairn toss" ring-toss game of some kind, or a pitch-a-penny game that might work like "split the pot." etc.
We should probably skip the air-rifle shooting booth.