One of the most awkward things about Soundwave was unlike other fliers, his arms were his wings. It was a small problem, merely in the fact that his odd biology left his wings wanting for sensation. After all, can't go getting overloads from other enthusiastic hand shakes. He jerks a little but other than that, not much there, but man he does know about seeker wings.

When you accidentally grab Starscream's wing in public to get his attention you learn about Seeker wings. So he just reaches up and grabs Jadewings.