So...
The pictures were not assigned on the Mac version.
They do appear somewhere as you can see them.
Presumably an iPad or iPhone.
You imply that on the Mac in System Preferences > iCloud the Apple ID is the same as the other device and Contacts is selected to sync.
By the same token you imply the other device also has the same Apple ID in the iCloud settings and Contacts is also set to sync.
If the Pictures are on the devices were you selected the Pictures and not getting to other devices you have not set up the Sync for the Contacts app the way you think you have.

7:29 pm Sunday; July 16, 2017
iMac 2.5Ghz i5 2011 (Sierra)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
iPhone 6 iOS 10.x and an iPad (2)