Disclaimer: I am going to write about photo sharing using Google+ with pages. I’ll admit that I am a big fanboy. I’m not going to bash Facebook, they have their own way of doing things.
For example, you have an Easter photo in your Google+ album. You can tag the people in the photo and they will be notified that they have been tagged (with the option to approve/reject). This is similar to the way Facebook shares tagging.
However you can also add a new tag with a PAGE name and the PAGE will be notified. Pages are like people (just like corporations). In this way the page manager can display photos from a number of different profiles at a single location. The daily photo theme pages work this way and they have thousands of viewers.
What do you need to do to get circled by a page? You need to circle it first!
Here is a screen shot of Page tag that was added to a photo. My dad’s furlough in 1943. On the right I clicked ADD A NEW TAG and entered the page name Poltrack Family. I could have added Honda or Ford but that wouldn’t make sense would it?