First, be sure that you are using the Google Chrome browser. Then, install the Verbling screenshare browser extension for Chrome here.
To share your screen during a lesson, click the "Toggle Screensharing" icon at the top of your session page.

Please note that you cannot share the browser window you are using for the session; you must share a separate window.
The "mirror" effect with multiple screens appears if you're sharing the "Video" tab of the lesson space. The video then shares itself and "mirror" effect is expected. When screen sharing, just click on the textpad or canvas or another tab you want to share.
While this feature will share your screen, it will not directly share your audio. If you do not have headphones plugged in, your computer microphone should pick up the audio if you are sharing a video with sound. But it's possible the sound quality will be poor for the student. If you need to simultaneously watch a video with your student that includes sound, we recommend using the Watch2Gether app.