Dabbler, while an alien, still has a face that follows the same basic rules of proportion as all non-Sydney faces.
But in other matters of drawing (line weight, hatching, fill, shading) Dabbler does not match up with the other characters either.
Both Sydney and Dabbler are closer to manga styles, but each takes from a different style of manga. Dabbler's is closer to the style of drawing, inking, and coloring used for many anime, as opposed to the sketchiness of Sydney.
Maxima, by contrast, uses a western style in her designs. (Though all the characters have chibi forms, I suspect....) Line weight and hatching.
Not defending the style used for Sydney, by the way, nor that used for Dabbler - I am not much of a fan of manga nor yet of anime.
The Auld Grump