Click on the flag and draw while pressing your mouse down. Click on the reset button to well... Reset =)... Watch this video at CS First to learn how to build it: https://csfirst.withgoogle.com/c/cs-first/en/art/graffiti/introduction-to-graffiti.html If you're a teacher: Lesson plans are also available on the CS First site. If you decide to sign up for a CS First account, you'll be able to track your students' progress, order physical materials (kits), and access your students' projects in Scratch.