I liked this photo because of the sheer joy expressed on the face of the girl in the background and the look of cautious expectation on the one in the foreground. Does the caption fit? I think so. I've often wished that I could just take the pictures myself, and I could get exactly what I needed. I suppose I could draw it, but that takes a LOT more time than just using existing photos. However, I do think that, as a writing exercise, captioning is quite beneficial. You see, you don't have the luxury of setting a scene. You have to use an existing situation, create characters out of that situation, give them a history, and then tell a short story. It's like literary improv. Are the stories always good? No. But I think that I grow as a writer with each one.
Anyway, that's all of the writing talk I'll bore you with today. On with the caption!