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