Sharing static card to G+ circles

We have a little nodejs app pushing a static card into the timeline through the Mirror API.

Once received, a Glass user is going to share the card with his or her Google+ circles. It worked quite well until, I think, the XE18.3 update, when the 'Share' Glass menu suddenly stopped showing G+ Circles as an option to share the card with.

Was this a planned modification to the API, and if so, what is considered now a recommended workflow to share a static card with G+ Circles? Or am I just doing something wrong?

Here is a little snipped how the card is created:

$c.google.auth(user.google_tokenRefresh, function (err, token) {
    if (err)
        return console.log("ERROR #3 in tracks.add at 'get access_token from google' : " + JSON.stringify(err));

    require('/node/node_modules/request').post({
        url : 'https://www.googleapis.com/upload/mirror/v1/timeline',
        qs : {
            uploadType : 'multipart'
        },
        headers : {
            'Authorization' : 'Bearer ' + token.access_token
        },
        multipart : [{
                'Content-Type' : 'application/json; charset=UTF-8',
                'body' : JSON.stringify({
                    menuItems : [{
                            action : 'SHARE'
                        }, {
                            action : 'DELETE'
                        }
                    ]
                })
            }, {
                'Content-Type' : 'image/png',
                'body' : buffer
            }
        ]
    }, function (err, resp, rdata2) {
        console.log(rdata2);
    });
});

Thanks!