In defense of the explanation, sometimes it's asking for an unnecessary mental leap of the reader to think of a bit array as a number, especially if the reader is not accustomed to thinking in base-2 or base-16 number systems.
(I should have probably used 32 octets so that it fits neatly in 256 bits)
The "mapping" you may be referring to is happening outside and subject to how your brain /your browser interpret it. (How do you know that when I posted the comment, that I didn't supply the raw bits of the number?! ;-))
Anyway, it was just a joke for low level-programmers I guess. Have a good day ;-)