Yeah, he is, but I'm pretty sure it was taken during a day that they had a team photo shoot or something (which was sometimes done at home with road uniforms).
Here's a clearer shot of the top portion of Joey's photo:
Here's a shot of the left field adverts in Yankee Stadium that year (excuse the size):
You can see the same Philip Morris and Vat 69 ads behind Gehrig's head, which again, I know are a bit blurry. I've also circled where Gehrig was most likely standing when the photo was taken.
Here's a better look at the signage from the World Series that year:
Graig