Yes! You can screen share to watch anything you want from within a Room! If you have a strong internet connection, you can view any streaming service in another Chrome Tab and then screen share that Tab into the Here room. Click the monitor button on the tool bar (first button from the left).
Be sure to check off "Share Audio" in the lower-left corner and make sure everyone uses headphones
Once the screen is being shared in the Here room, you can set it to fullscreen. To set it to full screen, select the 3 dots under the screen share window that pops up in the room and then select Fullscreen. It looks like this: