Ultimately, the issue was that the light source was coming from behind the subject. If you stood on the other side, slightly off to the side so that the light hits the front directly without your shadow, it would have been more visible. Even better if you put it closer to the light source.
Also, I don't know what iOS your iPod Touch is running, but the iOS default camera has an exposure slider next to the focus square now. Slide up for brighter, down for darker.
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The bigger issue with darker photos is that the camera doesn't focus as well and leaves the lens open slightly longer, creating a grainy, blurry effect.
Not complaining. Just trying to help for the future.
BTW, bulbs get dimmer overtime to that degree? Must be a CFL. I don't see it with my few remaining incandescents or LEDs.