You've got them mixed up I think - left side of the brain is logical, practical etc and right side is creative etc
Left side of the brain controls right side of the body, and vice versa. So if you're left brained, your right thumb should come on top. If you're right brained, your left thumb should come on top. Theoretically, at least.
I always test 50-50 on left/right brain tests, right handed. My left thumb comes on top, but right over left when crossing arms. I can only see the dancer counter-clock wise, now matter how hard I try to make it spin the other direction...
EDIT:
"Left brain dominant individuals are more orderly, literal, articulate, and to the point. They are good at understanding directions and anything that is explicit and logical. They can have trouble comprehending emotions and abstract concepts, they can feel lost when things are not clear, doubting anything that is not stated and proven.
Right brain dominant individuals are more visual and intuitive. They are better at summarizing multiple points, picking up on what's not said, visualizing things, and making things up. They can lack attention to detail, directness, organization, and the ability to explain their ideas verbally, leaving them unable to communicate effectively." - similarminds test
Then where do ENTPs fit on this chart?!