Penelope K, by the way - Stars

Penelope K runs the Information Station, a place which contains all the answers to any question a child might have. To help her find the answers, Penelope is joined by her sock puppet, Squirm; Hank and Frank, two wise cracking fish; Trewey, the shadow rabbit, and music is provided by the Rubber Band. Penelope K receives some confusingly conflicting information about eggs when she investigates how strong they are. The Know Dome tells her they are strong like bridges, but when she drops one it breaks very easily. Birds sit on eggs to keep them warm, which means they would have to be strong after all. Penelope K is star gazing. Why do stars twinkle? Is there a giant pair of twinkly sunglasses in the sky making them look like they twinkle? Or is it just like the song suggests... that they are diamonds in the sky?