The New "Run the Endline" Signal

[Kansas Ref]

Can someone here demonstrate the proper performance of this signal?
From the appearance of it in the pamphlet, it looks like the ref would hold the ball with one hand, then with the other hand just wave it in front of his/her face (now you see me, now you don't) kind of motion--elbow bent and palms facing the ref

I would've thought it should be some kind of waving motion that is oriented towards the directional plane of the endline facing downwards--as opposed to upward and vertical--but then again maybe I am wrong?