Google Glass communicating with App Engine

I am making glassware (with the GDK) that makes a picture, requires a description and sends this data to the App Engine (to my deployed war). The Mirror API should then insert a timeline item in all Glasses that are authenticated to receive messages from this service.

What I do have:

• The logic to push cards to the glasses
• The Glassware running on the Google Glass that can take a picture and make a description by giving a voice command

I would like to know how to post this data to the App Engine so it can use my data to insert timeline items on his turn. I am kinda confused how to do this, because of the authorization I have to do.

You can use an HttpURLConnection or DefaultHttpClient to send the image and its description to your server. Refer to the accepted answer here for an example of how to implement this.