Can anyone identify the floor tiles used in The Great Pyramid of Meereen. I looked at all the 2x2 decorated tiles on bricklink and couldn't find them.
They are indeed quite beautiful tiles but unfortunately not official LEGO decals.
I believe they are his own original custom designs, as in another MOC for Portal 2 which can be seen at LEGO IDEAS he does confirm that he uses his own custom decals.
I based my design on the amazing 2012 Lego Cuusoo “Thinking with Portals” by Brickthing. I took his original design and added elements from Lego Dimensions and my own twist with custom decals and details from the Portal games.
There seem to be many more examples on that Flickr account.