For each element, the size of the outer/inner circle is determined by the posterior mean plus/minus two posterior standard deviations, thereby indicating posterior uncertainty. Color and opacity are determined by the posterior mean.
This is a supplement to: Gregor Kastner, Sylvia Frühwirth-Schnatter, and Hedibert Freitas Lopes (2017). Efficient Bayesian inference for multivariate factor stochastic volatility models. Journal of Computational and Graphical Statistics, 26(4): 905-917. https://doi.org/10.1080/10618600.2017.1322091.