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