I think the main idea of this passage is that learning and understanding can help you succeed.
Here are some quotes from the text that support my point:
“Alia glanced at the incomplete sketches, feeling like a cat in a dog show.”
“‘Every portrait begins with a circle,’ he said. ‘Then you create a series of lines.’”
“Alia was surprised by the structure and discipline involved in drawing a portrait.”
The first quote shows that Alia doesn't really know how to draw portraits yet because she hasn't learned the skills. The second quote shows that her teacher is explaining how to draw one, and Alia is starting to learn and understand the process. Finally, the third quote tells us that Alia is impressed with how well her portrait turned out after learning how to do it.