I know he looks (pardon my language) retarded, but he wasn't. It's just alcohol laughter. ;)
There are no coincidences. I went to Krakus mound to shoot some night city panoramas. While waiting for long exposures, I noticed two strangers standing close to me, who seemed to have really good time, laughing a lot. I realized one of them was a bit drunk, so the other one was taking care of his friend. We started talking, they sat next to my tripod, and - having good humour - we laughed a lot. In one of that moments - poof, that shot just came to life, with a litle help of that sober one's smartphone light.