Ben,
I think it's fair to say that you've got a Gehrig rookie photo in your hands.
Though the '24 Reach book shows the '23 team composite, since it was probably laid out and printed early in the year, in my opinion, there's VERY little chance that the photo could have been taken in early '24. And besides, Gehrig was with Hartford for the majority of the season until late August. Though he was with the big guys in spring training that year, Huggins had him sent down to the Eastern League on April 15, as soon as waivers cleared. Ben's photo shows Gehrig clearly at the big ballpark in the south Bronx, so there's no way that he even appeared in the first game of the season for the Yanks since they didn't open up at home until April 23.
Also, check out one of the other Gehrig Conlon shots from '24:
You'll notice that if nothing else, Gehrig's sleeves in Ben's photo are the longer length, rather than the above, which has them trimmed at the elbow. So, that should at least mean that the photos were not taken on the same day, as a lot of Conlon's action/posed photos from the same year were (see some of Ruth's portraits from '27).
Also, you can see that a crowd has started to gather in the stands, so there's no way that this isn't before some sort of game. But that's not even the most important part of Ben's photo.
Now, the light and shadow placements on Gehrig and the dirt show a lot of interesting stuff. If you know Yankee Stadium very well, you know that left field was always the sun garden, and the right field grandstands would cast their shadow somewhat along the first baseline. The angle and length of the shadow changed in relation to the angle of the sun as it went across the sky, which also varied from month to month. In September and October, the shadow would be much longer and really echo the shape of the grandstand almost perfectly. And, during batting practice for a game in the 1920s, which would be sometime around 1-2 at the earliest (regular season games started at around 3-3:30), that grandstand shadow would extend to right around home plate. If you've ever seen footage of the World Series from the 1950s - especially during Larsen's perfect game - you'll see how the shadows travel across the field over game time, but pretty much connect directly with home plate at one o'clock. The significance in this means that looking at Ben's photo, you can tell that the angle of the shadow is a lot 'shorter', thereby making it closer to the mid June or July months. Gehrig was NOT with the Yankees in those months in 1924, as he spent 134 games with the Senators.
However, in 1923, he
was. He supposedly made his first trip to Yankee Stadium on June 11 of that year, both to work out with the team and to watch the game from the bench. For the next few weeks, he rode that bench, got in a few spots here and there, and then eventually was sent back down to Hartford on August 1 before returning again at the end of September.
In other words, Ben, I'm pretty sure your photo is not only from '23, but probably from that first stint in between mid-June and August. The young, newly-turned 20 year old Gehrig was getting his first taste of big league ball.
Congrats!
Graig