Current results and perspectives on the dynamics of photoionization of small molecules obtained from the analysis of Molecular Frame (MF) photoemission are reviewed. The MF observables intrinsically couple the ionized molecular orbital and the scattering wave function of the photoelectron in the ionization continuum. The field of molecular photoionization has benefited from the development of experimental methods based on the determination of electron-ion momentum vector correlations using position and time sensitive detectors, as well as from advanced ab initio calculations accounting for electronic correlations which influence the different steps of a photoionization reaction. Key features of valence shell and inner shell photoionization processes, involving resonant and non-resonant mechanisms, are illustrated for small molecules of increasing complexity: we emphasize the general formalism which describes molecular frame photoemission for single ionization of linear molecules induced by linearly and elliptically polarized light after one photon absorption, and its extensions to recoil frame photoemission when non-linear molecules or multiphoton processes are considered. The rich information contained in molecular frame photoemission is at the core of a number of recent experiments at the forefront of molecular physics.