Evolution of spectral parameters as a function of the photon index Γ from the nthcomp fits. Color-coding indicates the estimated bolometric flux in units of 10^-8 erg cm^-2 s^-1. The top panel shows the ratio F_dbb/F_c and the middle panel shows the ratio F_seed/F_cor, which is connected to the photon index Γ of Comptonization power law according to Eq. (1). The data are consistent with the δ = 1/6 trend line (dashed lines) when the flux is above a critical limit F_x ≳ 10^-8 erg cm^-2 s^-1 and the spectra is softer than Γ ≳ 1.8. When the flux drops below this limit (F_x ≲ 10^-8 erg cm^-2 s^-1) and the spectrum hardens to Γ ≲ 1.7, the data are instead consistent with the δ = 1/10 track (solid lines). Thick lines correspond to the assumption i = 40° and thin lines correspond to i = 80°. This behavior suggests that during the initial outburst peak the seed photons for Comptonization come predominantly from the accretion disk, whereas below the critical limit – when the accretion disk has receded further from the BH – the seed photon come predominantly from synchrotron emission from the inner hot flow. The bottom panel shows that the reflection amplitude Ω/2π decreases during the flux decay, indicating that the reflector (i.e., the cold accretion disk) truncates farther from the BH as the outburst progresses.