What are the most useless beautiful engineering features of Apple devices?

It is interesting to see how much attention they pay to design details, just take a look at these pictures below:

Check the flashlight icon on the iPhone ‘Control Center’ menu, look how the button on the flashlight icon is set to ‘off’, now see what happens when you touch the icon and turn on the flashlight:

The small button on the flashlight icon goes up, indicating that the flashlight is now on.

Here is a side by side screenshot:

Edit:

The same goes with the Portrait Orientation Lock icon:

Well, that is some pretty cool attention to very small design details.

Edit 2:

Thanks for all the upvotes!

I am adding the following based on suggestions in the comment section:

The clock icon on the iPhone homescreen is a realtime working analog clock: