That light angle is a good catch. My best guess is that "Joe Mordica" is actually at the MS data center, and they shopped the CEO into the picture because he couldn't make it there in person.
I would imagine any decent photographer would use flash in these conditions. Not sure though how that shadow should look like in that case, probably should be much smaller if any, if the light source is in the front.
Anyway, I know there was a heated debate about those pictures back in the day but now it's kind of "meh". There is little doubt anymore that they did have a warehouse, and miners inside it, and the picture shows that, with or without the two guys there. Still doesn't answer the question if they mined anything back in August.