Follow Up To Cheney "X"
After hearing CNN's explaination of how the "X" appeared, and after seeing another image of the graphic, I'm inclined to give some credence to their story that it was a "glitch". The Drudge Report posted another screen shot of the graphic, with the X appearing white this time instead of black.
In this graphic, below the X, you can somewhat make out the following text: "Transition begins after 5 frames of black". It's tough to make out, because it's white letters over other white letters in the Cheney graphic. This fits with the CNN explanation...
"At the end of the speech the plan was to do, to have a CNN logo up on the screen and use that as the way of getting back from the speech back to you on camera and one of the many graphics we use here at CNN.I've used similar slates to denote where effects, transitions or video b-roll should be cued prior to usage on-air. There are many ways that a graphic could make air unintentionally. If it preceeds a keyer graphic or effect, and the keyer is taken live too early, it could happen. Most switchers (my experience is primarily with Grass Valley machines) will give you a transition preview, which keys the graphic on a preview monitor. An incorrect keystroke during preview would bring it up live. There are other ways it could happen by operator error, and probably as many by equipment "glitch". Remember, here's what a typical broadcast switcher might look like...
A majority of graphics we use on the air, we use as a big x to identify at what point should the tape be cued up.
This is the x you see in the control room but it is never meant to be seen on the air. "
They can be very complex. In this situation, I've gotta believe it probably did happen in error.