Digging around some Czech sources I found this captioned photograph:
It shows the position after White’s 9.Bd3. Alekhine is deep in thought, and will play 9…f5 next.
If you click on the image to enlarge it, you can see that Alekhine’s clock is running (the plunger is up on his side, down on Stahlberg’s). That clearly indicates to me that this photograph was taken while the game was ongoing (that, and the onlookers poses – including the fact that some are looking at the photographer, which would almost never happen if the image were staged! – Ironic isn’t it?)
Winter actually has a Chess Note on this photograph (CN 6525 (scroll down)). It cites the following photograph:
In a later item, CN 6947 (scroll down), Winter uses this uncredited photograph of a young Stahlberg:
Now, given the photographic evidence that the game was in progress, it is almost certain that the American Chess Bulletin caption was wrong. I can make several additional points to support this viewpoint:
- When opponents review a game they inevitability seat on opposite sides of the board, replaying the game from the viewpoint of their color.
- During a game a player would never sit at the elbow of their opponent.
- The seated man on Alekhine’s left is smoking, a lit cigarette can be seen in his right hand. Though Stahlberg died young of a heart attack, at the age of 59, I don’t believe he was a smoker. At least, I’ve never seen him smoking in any photograph.
- Stahlberg parted his hair. The man in the photo did not. Moreover, Stahlberg doesn’t wear sideburns, the man in the photo appears to have modest sideburns.
- The man in the photo is wearing a bowtie. I’ve yet to see any photograph of Stahlberg with one, his choice of neckwear was a tie.
- The man in the photograph had hollower cheeks, and wore a light coat.
No single argument is conclusive, but the preponderance of evidence clearly points to the one conclusion. And, I might add, the burden of proof should be on the positive assertion, given the prima facie evidence that the game was in progress (note Alekhine’s concentration as well).
To finish, here is a cover of a Czech magazine from 1934, that Winter makes note of, perhaps because the imagine has been doctored: