this is in
T transforms (x,y,z) to (-y+zh,-x+zk,z) so that the z coordinate is unchanged
the first two rows reflect in the line y=-x and then add zh to the x and zk to the y coordinate respectively, the third row leaves the z coordinate unaltered.
if (x,y) is transformed to (x+h,y+k) then we are in the plane z=1.
So i guess
is the same transformation but in the plane z=-1