What do all of the ceiling pieces of the sistine chapel have in common?

They are all pieces of art that Michelangelo painted. Let me know if this helps.

The ceiling is that of the Sistine Chapel, the large papal chapel built within the Vatican between 1477 and 1480 by Pope Sixtus IV, for whom the chapel is named. It was painted at the commission of Pope Julius II. The chapel is the location for papal conclaves and many other important services.[1]