• If you use iCloud Photos, photos and videos that are outside the Photos library aren’t stored in iCloud and won’t be accessible to any other Mac or device that uses iCloud Photos. If you disconnect the device where the files are located, or move or rename the files in the Finder, Photos won’t be able to locate them.
• Photos also uses intelligence to find and focus on only the best part of your photo for better previews. Rediscover magical moments from your library. The For You tab contains all your Memories, Shared Album activity, and the best moments from your library.

To import iPhone pictures to Photos on macOS, follow the steps below:
1. Launch Photos app on macOS and connect your iPhone to MacBook, iMac, etc. via USB cable.
2. Tap 'Trust this Computer' on your iPhone when you receive a message.
3. Select photo items you wanna import to Photos for Mac. Or just choose 'Import All New Items'.
4. Pull your iPhone out of your Mac after the whole process is done.

The photos app is in the Application folder not your Pictures folder. The library that holds your images is in the Pictures folder. I think you're confusing the library for the app itself. Active captian app mac. Its a container type file and if you right click and and select show contents. Applications folder in Finder shows all your Mac apps and you can quickly manage your apps in this folder, no matter the apps are downloaded from App Store or websites. If you can’t find the application folder on Mac, it may cause you inconveniences, for example, deleting apps.

Search In Finder Mac

Note: if this is the first time for you to connect iPhone to Mac Photos app, please don't undo 'Open Photos for this device' option at the top menu. If you accidently undo this option, please disconnect your iPhone to Mac, shut down and reboot your iPhone. Quickbooks app for mac desktop is not working. Then re-connect iPhone to Mac Photos app to import pictures again.

Show Library In Finder Mac

To export pictures from Photos app to Mac, do as following:
1. Choose the pictures you plan to export to macOS.
2. Click 'File' on the top toolbar of your MacBook/iMac > Tap 'Export' > Tick 'Export XX Photos'.
3. Select export image format (JPEG, TIFF, PNG), Info and File Naming > Click 'Export' button.
4. Open 'Finder' on MacBook, Mac Mini, iMac desktop to search and find the pictures you export.