Reconstruction of a simulated flare using dynamical imaging (Johnson et al. 2017). From top to bottom: simulated images of a flare with a period of 27 min (model B of Doeleman et al. 2009); simple dynamical imaging without the LMT (no short-baseline points constraining the source extent); dynamical imaging using ℛ_Σ without the LMT (the second moment regularization offsets the lack of short-baseline constraints); simple dynamical imaging with full EHT2017 sampling; dynamical imaging using ℛ_Σ with EHT2017 sampling. Using ℛ_Σ significantly improved the quality of dynamical reconstructions both with the full array and without the LMT. NXCORR values against the model images are shown in the top left corner for each reconstructed snapshot. The variations in the resulting FWHMs of the reconstructed images are visually evident.