Cliffjumper is Optimus Prime's crack shot sniper, possibly his most trusted friend and ally. But he is dead.
The normal Cliffjumper is mistaken for the real Cliffjumper.
Sideswipe said he saw the real Cliffjumper die right in front of him.
According to Sideswipe, the "normal" Cliffjumper not only looks like the "real" one, but also talks like the "real" one. The only difference of appearance between them is their colors. Which means even a Cliffjumper from mirror-verse is a redeco of Bumblebee, poor guy.
Of course, Bumblebee in that world has a different body now.