Welcome to the aneurysm that is the Google design guidelines.
>Surfaces and edges of the material provide visual cues that are grounded in reality. The use of familiar tactile attributes helps users quickly understand affordances. Yet the flexibility of the material creates new affordances that supercede those in the physical world, without breaking the rules of physics.
What a breath of fresh air. They want the designs to seem as realistic as interactions we have in the real world.
Let's try it out:
That's right. According to google (and reality, apparently), pressing a button is actually the opposite. You're really pulling the button toward yourself!
