It’s a recent new feature to vote separately on whether you agree/disagree with the comment:
You can now vote separately on whether you appreciate a comment (and think more people should see it) and on whether you agree with the contents of the comment. Only the first of these will affect the poster’s karma.
What is the vote with the “x” right next to the karma vote?
Hi Michael!
It’s a recent new feature to vote separately on whether you agree/disagree with the comment: