If you narrow your browser's window, and click on the hamburger menu icon, it transforms into a cross with a circleIf you click on a pulsing circle, the line of text on the right changes
The combination of great design and diligent app development.
Your see this line when the page loads, and after clicking the upper left circle on the bird.
You have clicked the bottom circle, try another.
Now you've clicked the circle on the bird's chest.
If you click the second circle from the bottom you see this line.