Um, did you miss the following paragraph (emphasis added)?:

To make an outrageous metaphor: our brains run a system rather like Less Wrong's karma. You're allergic to cats, so you down-vote "cats" a couple of points. You hear about a Palestinian committing a terrorist attack, so you down-vote "Palestinians" a few points. Richard Dawkins just said something especially witty, so you up-vote "atheism". High karma score means seek it, use it, acquire it, or endorse it. Low karma score means avoid it, ignore it, discard it, or condemn it.

And...the rest of the post? Upvoting/karma as a metaphor was the whole point! In such a context, it was perfectly sensible (and even, I daresay, slightly witty) of me to append "literally" to the above comment.

(Honestly, did I really need to explain this?)