The ice features seen around the protostar IRAS 15398–3359 do not directly reflect the true chemical composition, because the observed signal is strongly altered by Radiative Transfer effects.

Source: https://arxiv.org/abs/2604.27133 Here, Radiative Transfer explains how light changes as it moves through gas, dust, and ice around a protostar. They calculated the freeze-out temperature at which a gas molecule will stick to dust grains as ice or evaporate back into gas in a space. They