This technical note examines collective luminescence from a diagnostic, regime-based perspective.Rather than focusing on microscopic models or material-specific mechanisms, collective emission is analyzed as a transient operational regime characterized by synchronization, comparability, and finite temporal coherence among emitters. Within this framework, intense emission bursts are interpreted as observable traces of regime transitions, marking the collapse of metastable collective compatibility conditions. Superfluorescence is discussed as a limiting case along a continuum of collective emission regimes. The analysis is deliberately non-ontological and does not propose new physical mechanisms. Its purpose is to isolate general structural constraints governing the emergence, persistence, and breakdown of collective luminescence across different physical realizations.