... its not wind... (bwrwrwr). You sir, lack the power of observation!
Nice aerodynamic effect though!

It's a subtle wind current acting upon the single leaf shaped like the natural airfoil that it is. Maybe an oscillation effect set-up on that springy stalk. Be great fun to catch this tripping shrooms in the woods...If you walk in the forest enough you'll see it-

Maybe a mouse trapped in the plant

next he'll exaggerate and say it was God in the form of a "burning bush" speaking to him to take off his shoes he's on hallowed ground.

Resonance......look up the tacoma narrows bridge collapse for an idea on a much larger scale

Gallopin' Gertie!

Ive seen several physics lecturers from diff uni's use the tacoma narrows event as an example leading into resonance lessons. Its pretty cool

Nature kicks serious fucking ASS!

The plant is saying, "No, don't hold the camera that way!"