This guy is Imgur famous for doing structural integrity inspections of houses, requiring him and his team to go under the floor of houses and film the dodgy and interesting stuff found there. I think they’re in the California area, so they get called to inspect after the seismic activity they have there, and often find buildings that weren’t built to code in the first place. Your photo was like the classic beginning of a “Things seen this week during structural assessments” post.