The green and red post-its have the same orientation, the adhesive is on the top for both. So when you peel the green one off, you're peeling the adhesive right

The green and red post-its have the same orientation, the adhesive is on the top for both. So when you peel the green one off, you're peeling the adhesive right-to-left across it, whereas when you peel the red one off, you're peeling it from bottom to top almost all at once.