Waveform — peaks flattening at the dashed ±1 lines (turning red) is clipping

Spectrum (log frequency) — peaks are the combined overtones; red lines mark the implied fundamental and its harmonics. In just intonation peaks land on the lines; in 12-ET they drift off

Autocorrelation (lag/time) — a tall peak at the red line (the implied fundamental's period) means the chord locks into one periodic tone. That lock is the "ring"