Western and Wilshire in 1925

Got this old postcard via eBay the other day. It shows Western Avenue from its intersection with "Wiltshire" Boulevard, from around 1925. I bought it almost as an afterthought, but having it in hand and looking closely at it, I've found it to be quite interesting.



First, just to get our bearings, the street corner at lower right by the blue car is where the Wiltern Theatre would be built about half-a-decade later. Today, across Wilshire, where the Standard Public Market is in the postcard, stands the new Solair residential and retail center. The neighborhood's changed quite a bit since 1925, hasn't it!

What really intrigues me in the postcard image is the traffic control device in the center of the intersection. Anyone know what that gizmo's called? It appears to have just a single red light, or maybe it's merely a red reflector, so it's not really a traffic signal as we know them. Also, look how the cars are bunched around it. It's almost like the sign is a marker for a place where autos are supposed to turn; sort of like a modern roundabout. Notice how the driver of that blue car is signaling for a left turn, but he's over near the right side of the road. I don't know – I've never seen this kind of traffic control before. Anyone else got any ideas, or maybe know the actual story behind this device?