Isolate and copy on a Mac?

So, I like the new feature where I can isolate and copy a person or item in Photos (in IOS or iPadOS) just by pressing and holding on it, then moving it to where ever I need... BUT...

I was trying to figure this out on the Mac. I learned that if I right click (or hold "Control") I'll get the option to "Copy Subject". I then see the white line outlining the subject.

BUT...

As soon as I move my mouse, the feature disappears. I can't seem to copy it.

How do I do this?