I have no idea what these are. I absolutely love the photo though. You know that something has happened. Might not be interesting to those that left the cans there, but it is a story none the less. A minor mystery. I like how the composition is asymmetrical and off balance. It adds to the feeling that something is missing. That something had just happened.
Of course, I doubt all those things were going through Danny’s mind when he took it. Maybe he thought it looked nice or maybe he was just testing the camera. We’ll never know I guess.