Great: no shoes, a few laptops out
There's a kind of social gathering I'm sure isn't exclusive to San Francisco but I've never experienced anywhere else. Everybody takes their shoes off at the door, people are milling about, and a few people have laptops out & will happily chat with you if you peek over their shoulder.
It's a very good sign in SF to show up somewhere and see something like this outside the door.
Not Great: vaporized who-knows-what
Not Great: vaporized who-knows-what
On Market St, they power wash the sidewalk daily (for obvious reasons).
So, walking home you'll feel a gentle mist on your face and realize there's a power washer halfway down the block and the mist is 99.9999% just water but also 0.0001%...something else.