Why are the tiles in ALCATOR wonky/not aligned to a grid in this image?

The image of ALCATOR on Wikipedia has a nice closeup of the tokamak with the inner transformer wall covered by moly heat tiles. If you look at the tiles they are all rotated at an angle diagonally in columns so that instead of a nice checkerboard tesselation it's rotated squares.

Anyone know if this is some temporary thing with tiles during maintenance or if it's actually something as part of the design? The offset pattern is continuous in all columns maybe a bit more so in the top half rows and as the tiles stay rotated until they disappear into the ceiling of the chamber which doesn't suggest some installation error. Maybe that angle has something to do with the angle of the field lines in the plasma and the drift paths of ions?