Its a illusion look in the middle it looks like there is something inside it

About

Tynker is the world’s leading K-12 creative coding platform, enabling students of all ages to learn to code at home, school, and on the go. Tynker’s highly successful coding curriculum has been used by one in three U.S. K-8 schools, 150,000 schools globally, and over 100 million kids across 150 countries.