Apple

This more in-depth video from WWDC Developer Sessions about the nuances of Liquid Design language have changed my perspective on it. There are a ton of thoughtful interactions intended in this system like automatic opacity switching when over text, increased shadow when over other elements etc.

This shows though, as much of what you’ll see in the video does not resemble what they showed on the keynote, that what they had ready for demo was very far off from what it was supposed to look like. 

I hope they can deliver the necessary tweaks by September. 
https://youtu.be/IrGYUq1mklk