The realization space is
  [1   1   0        1   0   1   1                 0           x1           x1    1]
  [0   1   1   x1 - 1   0   0   1         x1^2 - x1    x1^2 - x1         x1^2   x1]
  [0   0   0        0   1   1   1   x1*x2 - x1 - x2   x1*x2 - x2   x1*x2 - x2   x2]
in the multivariate polynomial ring in 2 variables over ZZ
avoiding the zero loci of the polynomials
RingElem[x2, x1, x1 - 1, x1 - x2, x1 + x2, x1*x2 - x1 - x2, x1^2*x2 - 2*x1*x2 + x1 + x2, x2 - 1, x1*x2 - 2*x2 + 1, x1 + x2 - 1, x1*x2 - x2 + 1, x1 - 2, x1^2 - x1*x2 + x2, x1^2*x2 - 3*x1*x2 + x1 + 2*x2, x1^2 + x1*x2 - 2*x1 - x2]