Smooth muscle is not attached in the way that striated muscle is. There are many differences between smooth muscle and striated muscle. Smooth muscle is not under voluntary control and is found in the gut, blood vessels including the heart, the pupil of the eye, etc..
Striated muscle, including the muscles of the tongue are anchored at both ends.
It was the attached word that was getting me. As I was thinking about smooth muscle as well, but really every muscle needs to be attached to something or it's just floating. Maybe I am too literal!