Does Google+ to new Photos app "cut & paste," or "copy & paste" archives? Does the new Photos app duplicate photos from Google+, or does it move them completely over?

I pay $1.99/month for my Google Storage and was wondering if current system will delete the copies in "traditional" Storage of photos, when it transitions my media into the new Photos app. I was hoping to avoid duplication.
When you run the Photos app for the first time, it asks you if you want to display your pictures from Google Drive in the gallery.

It also states that the pictures will stay in Google Drive unless you move them.

I haven't (yet) found anywhere in the Settings that lets you change your mind.  If I do, I'll put up a screenshot.