You can put the content at the full screen and then make a "Print Screen" selecting the scene that you may like to show. It could be exactly the same as presented in the video source, or other that you prefer. To do so, just click on your keyboard the key located at the top right side " Prt Scr" or similar. It will capture the image.
When you proceed to save the picture in TOWATCHNOW, make sure that you know where the picture that you saved to load is located. Depend on the resources that you are using. See an example