Also if you double post without bumping and delete the extra comment, it gets bumped too.
Posted under General
Lick_King said:
For privileged/builder level and above, editing and deleting comments doesn't bump the image.
We're not talking about just editing but rather editing a comment you just posted "without bumping". That does bump the image, to wherever it would have been if the initial comment had been posted with bumping.
Updated
That's correct. I believe that also goes into the 2-per-hour limit.
Editing a comment doesn't seem to distinguish between whether the comment was originally posted with or without bumping. I'm not an expert so I can't describe my speculation in good words, but it's probably because the bumping function has nothing to do with the comment itself.