That's a mail drop.
Ah, ok. Not from San Francisco. Never been there. Didn't know.
Although, I have to say that I have worked for companies that had no office anywhere at all. Just a mail drop, and all employees work out of their own houses.
I'm not saying that this is what Coinbase does, but it's worth considering that it's a possibility.
Yeah, the condo they work out of is over next to the Caltrain station. They are right across the street from the new Safeway. I love that store, it's so well designed. I think they are working out of the condo. I took a bunch of pics of the building if I can find the link where I posted them long ago I'll put it here.
I know the exact building you are talking about and I believe that is where they started off from.
I believe this new office is the One Front Street office because the CEO had a picture that had a building in the back ground that was used to pin point them. He has since removed it off his twitter.
Edit: This is the building that was used to pin point their "office" building.