W1zardK1ng If you take photos or videos with Pixel/Google Camera, then the preview will show up in the preview circle thing.
Anyone who has sandboxed Google Play installed on their phones cannot install Gcam services provider because of package conflicts.
There is a small app that has been suggested by other community members in the past called GPhotosShim. I haven't tried it out, so I cannot personally vouch for it, but I hear the app redirects intents to open Google Photos with your default gallery app, or something like that. Maybe this is the functionality you're looking for?