S90 versus 9 year old Canon S100

I was surprised to see the difference between two photos shot on auto. The only change done to the S90 image was resize it to equal the same size as the older camera. You would think that the S90 would destroy that of the year 2000 Digital Elph.

S100 image, shot on auto, (only has ISO 100) flash automatically fired:

S90 image, shot on auto; flash did not automatically fire: