It's the 747-SP of the Metro Rail Lineup.
We spotted this horizontally-challenged subway on a transit-oriented food adventure to Mama's Hot Tamales, Grand Central Market, Lost Souls Cafe, Philippe's, and Scoop's this weekend. Although these two metrorail cars may look lonely, shortening trains is one way to control costs while keeping headways low (having more frequent service) during times of decreased demand for service (mid-day on a sunday, in this case). I understand from MetroRiderLA that they were running mid-day on a Monday as well.
I did see a 1-car green line train a few weekends ago, but I didn't get a picture of it.