They're showing a cartridge flying through the air at the watch...
Cartridges don't fly. Bullets fly.
The casing (the big piece o' brass) houses powder, and has a primer (small explosive charge) at one end...when the primer is impacted it ruptures, explodes, lights the powder...powder burns and gasses expand, forcing the bullet out of the barrel.
This is similar to a story one of the news outlets covered about a house in Iraq. A woman came out to meet the media, insisting that soldiers had shot up her house. She had two handfuls of unfired cartridges...
The picture could possibly representing someone throwing a catridge/bullet at the watch?
This is the only thing flying out of the end of the barrel:
Ha, I knew that. I'm just not a gun person so that didn't pop into my head when I was looking at the pic.