Symmetry is when two sides of an object is the same of the other side.
If you put a line in the middle of the object then it will be even.
If it is not the same it will be asymmetrical.
This slide is about visualizing from reading a book.
Visualizing is when you read a book and imagine if you where the person in the book. The things you do in Visualising is what you can hear, smell, feel and imagine.