Silent Judging is what you do when you disapprove of a comment someone else has made. The irony is that you'd never know if someone on the internet is judging you silently, so they have to say "I'm judging you silently" which isn't really silent at all. Unless you type very quietly.
Tom Cruise's character in the movie Magnolia, when asked by a reporter what he was doing. (He was just sitting there looking at her.) His response: "I'm silently judging you." She didn't respect his cock, while he was well on his way to taming her cunt.
Silent Judging is signified by a narrow-eyed Philip J. Fry with an "I see what you did there" expression on his face. The two sentiments are very similar in appearance.