Schematic illustration of the mass growth and luminosity mapping assumed in the classical interpretation of compact H II regions (left) and in the IIM picture explored in this work (right). In both panels the stellar mass m increases with time until it reaches the final mass m_f, after which the star evolves on the main sequence (horizontal segment). Ionizing emission turns on when the growing star crosses the threshold mass m_ion at t_ion (dotted line, black dot). Classical picture: the formation phase is short, and the compact-H II stage is treated as a subsequent, comparatively brief phase of roughly fixed stellar mass, so that the embedded ionizing source is effectively already at m_f and L_{H II}(m_f) = L_OB(m_f). This work: the compact-H II phase occurs during continued accretion; the ionized emission is produced while m < m_f, implying L_{H II}(m) < L_OB(m_f) and motivating a comparison between the compact-H II-region LF at luminosity L and the OB-star LF at higher luminosities corresponding to the eventual m_f. The colored bars indicate the approximate timescales for our reference m_f ≃ 60 M_⊙ case inferred in this work; they are not to scale and are intended to illustrate the ordering of phases, highlighting that in the growth scenario the compact-H II-region phase is concurrent with the stellar mass assembly.