Person, vehicle, pet, package, any of the recognized objects that come with the AI analysis. The camera doesn’t know what it is seeing, it only sees “pixel change” as motion, wether that’s color change, lightness, darkness, any reason a pixel would change. When it detects motion that passes all your settings, the camera uploads the clip to the cloud. Once it is uploaded, the cloud analyses the full frame of the video looking for recognized objects then tags the video with what it detects, then you are notified of such.
Correct, that is how it works currently. This is why you are getting the stationary vehicle tags, because they are in frame.
I am guessing it will tag as a person. You may have to come up with a cool story about what’s happening for when the neighbors start asking what is going on with the mannequin in the driveway. 
Here are some applicable wishlist items you should vote for if you want to help them along!