You gotta wonder what the rear lighting arrangement was on that vehicle. Obviously no reverse or license plate lights, but it looks like just a single lens on each side. We know a brake light was required, and many cars into the 40's had only
one tail light. So, is that one tail light and one brake light?
edit: nevermind, figured it out here:
Powell Sports Wagon Registry. They had two lenses on left, blocked by the crouching man in that photo. I assume they're brake and tail light on left, and just one brake on the right. This was common in the 1930's and into the 40's, but unusual for anything this late(?).
I believe brake could double-duty as turn signal, at that time. Heck, I think USA
still allows red turn signals on rear, something most other countries outlawed decades ago.