As James mentioned, the Media TIles require a compatible format (MJPEG, JPEG, GIF, etc) and using an NVR like Blue Iris or TinyCam is a great approach to getting a compatible stream into your dashboards.
I wanted to throw another option out there for you. You could use the Media Tile along with the snapshot URL you mentioned (at a slower rate)… then set the action of the Media Tile to open a Hyperlink for an app that streams the camera (eg. TinyCam or the camera’s native app). That way you get a high level view of what’s happening and can click on it to get a live stream.
The format for opening an app from a Media Tile hyperlink action is the same as a Hyperlink Tile: