What is this?

[Jim Scott]

You have added a second camera, but you are viewing the scene through the default camera. In order to not see the second camera that you have added to the scene (and are currently not using) go to the Filter menu of the View window and click on “Camera” to deselect it (make it invisible) in the View window (the check mark next to “Camera” in the Filter menu will be removed). If you don’t want a second camera (it was added by mistake), delete it in the object list.

[Antti Ruotsala]

Thanks 🙂