The orientation settings let you choose left or right wrist and, separately, left or right facing Digital Crown, which means you can turn the watch "upside down" and wear it that way. But it doesn't have a setting for wearing it on the inside of the wrist.
What if I use the watch at my right wrist and set is as left wrist?
Edit for clarity:
this is to make screen facing my inside and watchOS knows about this.