It´s really nothing, but if you want my opinion: Something at the house in the center with the red stripes is the only thing that really let me see that its not a photograph. Sure not from knowing, only from seeing.
I cann´t say you exactly what it is, maybe cause there are less detail or less shadow. I think it is because it seems to have at every side the same luminanz.
I hope it was helpful for you, even if i give critique to such a great work!