You want to open the door with your Snom phone and see who is at the door? This is no problem if your door intercom system has a camera with Motion Jpg and can be addressed via a network address. The details for configuring video streaming on a Snom phone can be found in this article: Video Streaming with Snom Phones - Motion-Jpeg.
After saving, the input window clears and a phone book entry appears in the list above.
To add further entries, proceed from the beginning.