The video streamer service can stream a video source in MJPEG format. In order to stream the video, it needs to be attached to a video source. By default it will stream to port 9090. Most "real" browsers have the ability to display the video feed.
If you have a webcam, you can start an OpenCV service which will be the video source. Start the video streamer and attach it to the OpenCV service. Start a browser and go to http://localhost:9090/output , you should be able to see the video from the camera.