Hidden sidecar on unsupported iMac

Today I was doing heavy paperwork in the Finder due to my favorite organizer app has a glitch.

While using the new Catalina-feature rotating pdf in the Finder with Quicklook I see a new icon in the toolbar. A blue screen with a dropdown-menu that shows my both iPad Pro and my iPhone 8+.

Strange. I tap on it an voila the screen is send to my iPad and I am able to scribble on the pdf in realtime. The Mac-screen shows everything fine.

So far so good. Because of my iMac is a late 2013 and well off the system requirements for sidecar as shown here https://support.apple.com/en-us/HT210380#systemrequirements

I have checked my system prefs - no sidecar

and while in preview the toolbar lacks the sidecar-icon

I assume that a lot more Macs out there supporting sidecar without a hassle. It is just blocked by Apple for what reason ever.

So if you're Mac is not listed - give it a try. It is easy to use.

I have added some images to proof…