I didn't read the article, but just glanced at the painting. If a kid started lessons young, received proper instruction, and the kid is artistically inclined, it's not an impossibility. My daughter has been in structured art classes since she was 5, and the stuff that she did surprised me, but that's cause I'm completely ignorant of art and art instruction. Stick figures are my best effort. A lot of art classes, especially when younger, are carefully supervised. 10 kids to 2 instructors. And these kids that can and want to sit through a 1-1.5 hour class once or twice a week can progress pretty quickly.