Whitney's tongue a quiver

I have nothing

At different points in the video I get a good look at Whitney's tongue. When I fist saw her hitting some of the beautiful notes and watch her tongue quivering on both sides I could not imagine how that was done. My own tongue seemed so undefined and unrefined.  Singing to a CD in the car tonight I could actually feel the left tongue a quiver. The sound emitting from my piehole was probably more akin to the sounds of anguish than a song but there is a tremendous difference in my movement image of my tongue than years ago.