That indeed is true. The shot you see in the top of the ship When I did the background I couldn't composite the ship in any good way. I decided to flip it over and now it looks better, at least in my opinion.
What gives it away, is the secondary hull details. Look at its rear. The landing lip ...is on the roof? So shuttles land.. upside down to the rest of the ship?? That would be .."interesting" ...if purposely intentional.
Still yet though your design is another fan's design that should/could have replaced the last film production ship design.. due to it looking as the "giant turkey" as it was.