WHAT'S THE DIFFERENCE?

Now here's a strange thing. I may have mentioned Anna is your archetypal hunter-gatherer baby - she either wants meat, or berries. She eats most other things but left to her own devices, she'd happily pass on all carbs in favour of her beloved meat. When we buy a fresh, still warm loaf from ASDA or Tesco, she has to be coerced into eating it, just the same as if we buy a cold six hour old loaf from ASDA or Tesco. However if we bake a loaf at home in our bread machine, she suddenly abandons everything and devours most of the loaf simply with butter. No meat is necessary. How can she tell the difference at once between a fresh shop loaf and a fresh bread machine loaf?