There is a certain amount of randomness from Taylor with two or three piece backs. It has been reported here that some models come normally with two-piece backs, yet certain examples have three-piece backs. I noticed that the add does not say what year it is. That would fairly obvious from the serial number, if you have it. (You could also call customer service with the serial number and verify the model, appointments, authenticity, etc). The scarf joint on the head stock as pictured from the rear replaced the finger jointed necks, which I think occurred around 2005 or so. Taylor has always used a label to hide the neck bolts, so that by itself is not suspicious, but there should also be a label inside the sound hole mounted onto the back for easy viewing. This also looks like the older "blockier" dreadnought shape, which was softened somewhere around the same time that the neck joint was changed from finger joints to scarf joints. Also this looks like a generic aftermarket case, not an original factory hard shell case.
Given the lack of clear photos and a less than forthcoming response, caution is advised. But I may be a bit paranoid.