That squiggly thing is supposed to be Leavelle's forearm and hand. But, I am telling you, as a chiropractor, that were he doing that, his arm would be fractured. There are two long bones in the forearm, and there are no joints between the elbow and the wrist. It can't do that.
So, it is just bull shit, and the irony is that they didn't even need it here. They added it, but it was only to defend the Jackson photo. This photo was taken BEFORE the shot, so there was no need to do anything.
They just did that for the sake of consistency- consistency with the Jackson photo. And they modified the films the same ridiculous way.
Leavelle is the latest superhero: Elastic Man.