Does content modification in legal speak really have the same strict meaning as we tend to imply? I just checked Instagram's Terms for example, and they have no

Does content modification in legal speak really have the same strict meaning as we tend to imply? I just checked Instagram's Terms for example, and they have no mention of modification—though they obviously do compress and resize submitted images. This makes me wonder if altering a sequence of bytes (for example, after conversion to a different format) is really a ‘modification’ if it still represents the same work.