a down vote for "spacer.gif"? kids these days, just don't remember
Please note that the HN community takes a rather strict approach when moderating comments that contribute noise to the conversation. "Nice article!" comments are routinely downvoted. As is sarcasm, witticisms, memes, references and other styles of comments that occur frequently but do not contribute to the discussion. It's a knowingly doomed attempt to hold back the flood of noise that covers Reddit.
As it should be!
The ubiquity of the "funny == upvote" mentality is rather depressing, and I'm glad that HN (generally) tries to avoid that. It makes the comments section a much more interesting place to be (to me, at least).