The initial evidence for Bose-Einstein condensation (BEC) of Li7 consisted of image distortions that suddenly appeared as the gas was evaporatively cooled to near the transition temperature. We present results of a model of the imaging system used to produce these images. The model confirms that the distortions are a sensitive indicator of BEC, but shows that they make quantitative analysis difficult. We find that the distortions resulted from light scattered by the condensate, in conjunction with aberrations in the imaging lens.