A poster on the DC Message Boards under the name jackhenryjr pointed out the black hand on the card that Red Hood hands out in Batman and Robin #4. Because it's been a recurring image during Grant Morrison's run on Batman (and Robin), I thought a visual comparison would be useful, so here readers can see three examples placed together.
First, there is the poster for John Mayhew's film The Black Glove. Based on comments made by Man of Bats in Batman #681, the Black Glove himself seemed not to be thrilled with having been featured in a film, and eventually took revenge on those involved in the making of it, although that revenge seemed to be a long time in coming. The poster was seen in Batman #667 (the first mention of "The Black Glove") and Batman #677.
A similar image appeared on the screens of the Batcomputer when Bruce fell to the Club of Villains at the end of Batman #677. The image remained on the screens afterwards -- exactly how and why this visual display was arranged is not clear, but it helped set the mood. Since Batman was under psychological attack, maybe it contributed to the effectiveness of the "Zur En Arrh" trigger phrase that he heard simultaneous. Maybe Doctor Hurt just likes to do things with flair.
And now a very similar image appears on the business cards handed out by the Red Hood. It could be the imprint of the hand from the Batcomputer, or the other hand (hands do tend to come in twos). Note that if it's a palm, then the card advertising a "red right hand" is actually a left hand!
Given that the first two examples indicate the Devil and the third is accompanied by a line from Paradise Lost that is attributed to Belial, one other thing we can say about these three black hands on a red background is that they're associated with great evil. Is the latest example linked to Doctor Hurt? Or are Morrison and Tan setting a mood that goes beyond the efforts of characters in the story to arrange?