That, in effect, sets up a parallel karma system. There is the normal karma, visible and both up- and downvotable. And then there is the karma of dismissal which is unseen and can only go down but never can go up.
Besides that, the system implies personal “hide-this” flags for all comments. The Dismiss button, then, does two things simultaneously: sets the hide-this flag for the comment and decreases the comment’s dismissal karma.
That, in effect, sets up a parallel karma system. There is the normal karma, visible and both up- and downvotable. And then there is the karma of dismissal which is unseen and can only go down but never can go up.
Besides that, the system implies personal “hide-this” flags for all comments. The Dismiss button, then, does two things simultaneously: sets the hide-this flag for the comment and decreases the comment’s dismissal karma.
That would be the little minimise button in the corner.