Short-timescale magnitude–magnitude diagrams for MAXI J1820+070 across different phases of its outburst. Each panel shows g′ vs. i′ magnitudes for a specific MJD (indicated in the lower-right corner), with point-to-point connections highlighting the light curve evolution. The different phases of the outburst are indicated on top of each panel, reflecting the spectral state inferred from simultaneous X-ray monitoring.