I'm trying to set up a layout specific to Apple Watch 38mm but can't get it to work.
I tried clicking on the "Vary for Apple Watch 38mm" button, changing a constraint in the Attributes Inspector (view size height), and then clicking on "Done Varying". When I then look at the other device sizes, they all have the change I thought I was making to the 38mm device only. Can anyone offer some guidance?
I have the same issue which brought me to your post. I don't know how the "Vary for Apple Watch 38mm" works, but I found another way.
In the attributes inspector, there's "+" signs all along the left side. If you click one, you'll get a drop-down with different watch sizes. This way you can customize a given attribute for a watch size. Hope this helps.