Variable-angle reflection spectroscopy of a glycerol/heptane interface bearing 9,10-dibromoanthracene guest molecules made it possible to follow the variation of the guest optical absorption spectrum through the interface transition layer, Analysis of the surface optical functions resulted in local density profiles for 9,10-dibromoanthracene revealed the molecular field anisotropy and the preferential orientation of the guest within the interface, and demonstrated variations in 9,10-dibromoanthracene solvation shell mean composition and composition fluctuations,