I\'ve been able to retrieve everything but the contacts photo by following the API.
I can get the img url as well as the gd:etag from the xml returned. Below is the Goog
You would need to make a request to the url, but also include the access_token as a query parameter.
So, using your example, let's say if your access_token is ABCDEF123456ABCDEF, then the GET request you want to make is:
https://www.google.com/m8/feeds/photos/media/liz%40gmail.com/c9012de?access_token=ABCDEF123456ABCDEF