Ask HN: Why can't I see downvote or upvote arrows anywhere?
New CSS?  @media only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min-device-pixel-ratio: 2) {
    .votearrow { background-size: 10px; background-image: url("grayarrow2x.gif"); }
  }

  .rotate180 {
    -webkit-transform: rotate(180deg);  /* Chrome and other webkit browsers */
  …

It wasn't like that before, there were only gray{arrow,down}.gifForced refresh should help.