 Everything in the film revolves around a swirl, the same as in the  original drawings of the book. This includes the clouds. If you look  closely at in several scenes, several times the initials "C.H.",  "J.C.," and "R.H." briefly form as the clouds move. This stands for  actor Clint Howard (qv) (Whobris), actor Jim Carrey (qv) (The  Grinch), and director Ron Howard (I) (qv).