Diving right into the deep end of the pool with your first post? Okay.
A Michelangelo statue is a great work of art regardless of it's subject. I would speculate the yellow ball head was a wry commentary on altering anything that is considered a work of art. Michelangelo's David might have been a better choice, but then somebody might be upset over the nudity. I doubt the filmmakers were deliberately out to offend anyone's faith with it.
Was this statue digitally inserted, or was it really in the background?