Found the site in Google Maps, which identifies it as 101 Williams Avenue. Current occupant may be Mayta & Jensen, a building contractor: [start.cortera.com]. Found it by looking up the "Yosemite Place" building in the background then scanning around. BTW, the "new" Google Maps interface works, but the old one worked better.

Staring at Google, I suspect that it wasn't really 2 spur tracks for that building. It was one, with the track to the left being a drill track to serve the spurs (one with rail still in place almost down to 3rd Street) on Armstrong Ave. Not clear whether it connected to the Coke lead at some time in the past, or connected someplace else using the Armstrong Ave. trackage.

Given the location, somebody with old business directories and/or access to Sanborn Maps could probably provide more information.

Interesting, not far down Yosemite, there's a wye for turning Muni trains.

Suspect strongly that the other side of the railroad there, where there's a long thin mini-storage place now, was once a small yard for local traffic. Including Planters Peanuts, where the U-Haul & storage place is on Bayshore now (repurposed the building - those towers once supported Mr. Peanut). On the satellite view, you can follow where the spur lines ran for that and some warehouses in the surrounding area.