I had a student ask me and I had no answer: Why in the code are there no parameters set for the size of the ellipses, but yet they still get drawn?
Magic?
Seriously, it looks to me that it is a default size and that the lesson, itself, is focusing on students adding that information & adding it for them may be a little too easy for them. That being said, I’m just speculating. I’m not 100% sure why the engineers chose to do it this way.