[Eric in the Ozarks]

The floor looks like oil or grease was spilled on it for thirty years...

[TigerLikesRooster]

The place with stains on the floor looks like a loading dock or a storage room.

In all likelihood, you won't be shot for leaving some stains there.:-)

[mad_as_he$$]

I think it is wet. Somebody may have hosed it down just before the visit.