Camera Quality: Indoors, Good Lighting And Flash
No Zoom, No Flash
The cooler color temperature on the iPhone 4, which served as a boon outside and with lots of light, is actually a detractor indoors. The effect is far too obvious.
No Zoom, With Flash
If you need to use the flash, you'll find that pictures come out more evenly-illuminated on the iPhone 4S. This mostly seems to be the result of the phone's superior ability to compensate for poor lighting conditions, as the light meter doesn't register a change in the luminescence of the flash.
Full-Zoom, No Flash
The 4S continues to provide more detail in macro shots.