A simplified axi-symmetric 2.5D radiative transfer model of a YSO envelope (HST-1, 177–341, O’Dell & Wen 1994) in the Orion Nebula (NGC1976) is computed assuming only a spherical distribution of gas with a powerlaw density function. The model fits recent Hubble Space Telescope data (Bally et al. 1996) very well on 1015 cm scales, suggesting that the morphology of the ‘proplyd’ objects is due to photoionization on this scale rather than a direct wind-wind interaction (Henney et al. 1996). The fact that a simple spherical distribution of gas fits the ionization observations so well also implies that somewhere between the scale of the YSO accretion disk and the observed ionization front radius the gas distribution has changed.