How to make UI look like it's not part of the actual UI?

Question

I'm creating a theme picker. I want the user to have a mini preview of how theme looks like. So I added some sample UI elements on top:

I don't want the user to think that's actual UI, though.

Any advice?

Answer 1

I would wrap the "UI" in a container with a visible and distinguishable border and give the user an option to view the UI in full-screen if that makes sense for the context.

Alternatively, a kind of watermark might also work to notify the user that the UI isn't real.

Another way is to use Lorem Ipsum text in the UI, internet users know enough to know that it's placeholder and associate it with fake UI.