Bruce,
I think that photo is from the Special Collections at the University of Washington. E. Larson collection, Negative No. UW 12902. The original prints, were, I think, in an album of photos taken in Skagway during WW II. There were only a few of the railroad. Most were of the town and family, I think. I had five copy negatives and one 5 x 7 print made from each of the five negatives back in May, 1990.
My guess is that the photographer (possibly Mrs. Larson?) just happened to be at the right place at the right time. I have to wonder, though what sort of camera was used, because this print is pretty clear and seems to have stopped the motion of the car very well.
The box car is one of the ex C&S cars, presumably being delivered, not shipped out as surplus.
For me the big prize from that album was the one of the Skagway switch engine, which appears to be ex SN 4 picking up dump cars of coal at the dock.
Cordially,
Charlie
CVM
-30-