Late-stage coarsening in a 2D binary mixture has been investigated via direct imaging of "bubble" domains in an amphiphilic monolayer at an air-water interface. In a regime with growth exponent n≃0.28 for the mean domain radius, the radius distribution exhibits dynamic scaling, closely approaching a Gaussian shape. The local structure of disordered bubble patterns ensures short-range screening of topological charge. Pattern statistics correspond to equilibrated random Voronoi lattices and indicate a prominent role of entropy maximization. Pattern stabilization against bubble coalescence is attributed to electrostatic interactions.