Hi there KSav90,
If you see this photo in the conversation with your girlfriend but not in the Shared with You section in the Details view of your Messages conversation, let's first check your settings in regard to this feature. These steps from Send and receive content in Messages on iPhone show how to do this:
Control what shared content appears in apps
You can adjust your settings to hide an app’s Shared with You section.
1. Go to Settings
> Messages > Shared with You.
2. Turn off Automatic Sharing, or turn off Shared with You for a specific app.
If those settings are enabled and you still cannot see this one photo in this area, ensure your device is fully updated next. This installs feature improvements and fixes that can resolve unexpected behavior. This shows how to back up and update: Update your iPhone or iPad
If you are trying to accomplish something else, please provide more details so that we can continue to assist.
Cheers!