We report a detailed calculation of the angular distribution and polarization of the photoneutrons from $^{16}\mathrm{O}$ in the giant dipole region. The electric dipole ($E1$) amplitudes are obtained from a continuum shell-model calculation which reproduces the intermediate structure in the total cross section. A consistent interpretation of the angular distribution and polarization may be obtained either by (i) assuming a phenomenological giant quadrupole ($E2$) resonance, or (ii) by modifying the phase difference between the $E1$ amplitudes. In case (ii), we do not require any $E2$ resonance to fit the data, or, alternatively, the magnitudes of the $E2$ amplitudes used can be taken to be in reasonable agreement with those extracted from the polarized-proton capture experiment. As we show in case (i), there is a theoretical possibility for an $E2$ resonance. On the other hand, the present experimental results indicate the absence of such a resonance in the dipole region; this possibility is studied in case (ii).[NUCLEAR REACTIONS $^{16}\mathrm{O}(\ensuremath{\gamma},{n}_{0})$; giant dipole resonance; angular distribution and polarization of photoneutrons. Giant $E2$ resonance in $^{16}\mathrm{O}$.]