In general, photos hosted on google are not visible to all and sundry.
Making the photo "public" isn't sufficient - the viewer has to have a google account, and be logged in.
For example. I can't see Woolly's photo, even if he can.
If I copy the link and paste it into the address bar, I get "Sign in with your google account" rather than an image.
Woolly can verify whether it's properly visible or not by clearing all his cookies, then looking again.
I can't see LEE's photos either, but I gave up moaning ages ago.