Why does the crown on my Apple Watch sink into the watch itself ?

If you’re talking about it sinking when you press it, that’s because it’s a button. Like most buttons, it moves, connecting a circuit. Same with the volume buttons on a phone, side button on Watch, even power button on computer. Completely normal.

steph0907 wrote:

why does the crown on my apple watch sink into the watch itself

As Redpixel09 explained, the crown (technically the Digitial Crown) is also a button. Does it make a click when you press it? Does pressing it bring up the screen with all of the apps? If so, everything is working as designed.

If you're seeing something different, please explain.