For example, I have 100 images in one page, all of them with
alt attributes in this format:
alt="foo pics", alt="bar pics", alt="foobar pics", etc
pics be considered as stuffing?
You're not providing a complete
As for the main question, alt text does get indexed and if you keep repeating things over and over it's not fundamentally different from things like keyword stuffing.
That said, this is not at all what the alt attribute is for.