Does the Google JavaScript Client Library support sign-in via Google+ Page?

[Leo Herzog]

I'm trying to use the Google JavaScript Client API Library to authenticate and interact with the YouTube API on an internal web tool. The person signing in is a Google user who is a manager of several Google+ pages, and those pages are owners of YouTube channels.

I want the user to click my sign-in button on my page, authenticate as their Google+ page, and then my code preforms API calls to that page's YouTube channel.

Right now, I have something like this:

    var clientId = 'my-client-id';
    var apiKey = 'my-api-key';
    var scopes = 'profile https://www.googleapis.com/auth/plus.login https://www.googleapis.com/auth/plus.me https://www.googleapis.com/auth/youtube';

    var signinButton = document.getElementById('signin');
    var signoutButton = document.getElementById('signout');

    function initAuth() {
        gapi.client.setApiKey(apiKey);
        gapi.auth2.init({
            client_id: clientId,
            scope: scopes
        }).then(function() {
            // Listen for sign-in state changes.
            gapi.auth2.getAuthInstance().isSignedIn.listen(updateSigninStatus);

            // Handle the initial sign-in state.
            updateSigninStatus(gapi.auth2.getAuthInstance().isSignedIn.get());

            signinButton.addEventListener("click", handleSigninClick);
            signoutButton.addEventListener("click", handleSignoutClick);
        });
    }

    function updateSigninStatus(isSignedIn) {
        if (isSignedIn) {
            signinButton.style.display = 'none';
            signoutButton.style.display = 'block';
        } else {
            signinButton.style.display = 'block';
            signoutButton.style.display = 'none';
        }
    }

    function handleSigninClick(event) {
        gapi.auth2.getAuthInstance().signIn();
    }

    function handleSignoutClick(event) {
        gapi.auth2.getAuthInstance().signOut();
    }

    // Load the API client and auth library
    gapi.load('client:auth2', initAuth);

The buttons work perfectly. When my user clicks on the <button id="signin"></button>, it brings up the Google Auth dialog. If they authenticate as themselves, everything works perfectly. However, if they authenticate as a Google+ Page that they own, I get a console error:

TL;DR:

Does anyone know if the Google Javascript Client API library supports authenticating as a Google+ Page, and if so, how I should be handling what is being returned?

Thanks!