Really?! Making this project must have taken tens or hundreds of hours - if they are proud of the work, why not show it off? The video looks like it wasn't faked.

Did nobody look at the image after they generated it? If they live in a bedsit and don't have a nice windowsill, they could easily generate the background and if the product is vaporware they could drop a rendering over the top - I think that might actually be easier than training an AI on your product... I'll be grumpy at clouds next!

its a common thing on these sites. People complain about it all the time as alot of the models arent even printable. Some of these sites have a money making systems that are being exploited though. So there is a financial incentive to this as well.