Well some of them, like the bottle, I know are real. I've seen progress pictures, but the ones that cover whole streets are harder to believe. If you'd look at them from any other angle than the photo they'd look wrong, that would be insanely hard to work with, not to mention on such a massive scale. And then there is the texture of the tiles that is totally lost. It just looks like there was picture drawn and made transparent over a photo.
I don't say it's impossible, but it's crazy hard to believe.