How is that different than getting an email from Facebook that some friend has shared a photo with you? You would have to login to Facebook to view that photo.

How is that different than getting an email from Facebook that some friend has shared a photo with you? You would have to login to Facebook to view that photo. (and would therefore be counted as an active Facebook user) Anyways, your friend never attached an image, he just send you a link. It wasn't Google that replaced that image with a link, it's your friend that chose to share that image using Google's services instead of manually attaching it to every email. And yes, I am pretty sure that you are counted as an active user after accessing Google+ while beeing logged in with a Google+ account.