Väätäinen has so far stuck with Disney's female characters -- although he branched out beyond the heroines to include the villainous Ursula from The Little Mermaid. I can imagine several reasons for this. For one, most of the early Disney heroes were interchangeable versions of Prince Bland of Blandalot. I love Disney animation but I can't for the life of me remember anything that would distinguish the prince in Snow White from the prince in Cinderella. I remember the one in Sleeping Beauty fought a dragon. Later heroes, like Aladdin, Phoebus from The Hunchback of Notre Dame, or Li Shang of Mulan would, I imagine, offer an artist something to imagine to help build a character.
And for another Väätäinen is a guy, and historically guys have been known to paint pictures of pretty girls.
(H/T Buzzfeed via Yeah Right)