It's meant as a shorthand for "hex-encoded bytes".

You're really just interpreting bytes as characters in a different character set. "Visualizing hex bytes" suggests something slightly different, like using an emoji for each of the digits 0-9 and A-F (not much unlike the other proposals for writing hex digits, e.g. http://en.wikipedia.org/wiki/File:Bruce_Martin_hexadecimal_n... .)

What you believe "hex bytes" suggest to you (but falsely) are actually "nibbles"

http://en.m.wikipedia.org/wiki/Nibble

I'm confused. What you mean is that all bytes are hex bytes if you choose to look at them in hex, right?

No bytes are hex bytes. Bytes are bytes. You can display them however you like, even one byte as one emoji (what I argue to be too inconvenient representation in another message). But they are also not "emoji bytes." They are just bytes. As in "octets of bits," bit being a unit of information. And hystorically, the bytes weren't even necessarily octets, but some other group of bits.

This is semantics. For the record: I know what a byte is, and I am fully aware that numbers exist independently of any representation.

The tools for twiddling the bits of hex bytes are not always as readily available as those for Phillips or flathead bytes. Torx bytes are rarer still, and should be avoided.