Fanwork, real time model recreating Ariel's ghost form, attempting to merge the best renditions of her in the series. Burial wraps seen more in Blood Omen and the Soul Reaver games, more closely wrapped like in SR2. Half her face symbolically is either rotted away, or in my hint, possibly burnt away, The cinematic in BO1 shows her tip over one of the scales she lit with fire as she falls to her death. The substance within possibly could have melted her face as she died. Either way, her form represents imbalance in the land of Nosgoth. Bound to the Balance Pillar, I imagine a ceremony at the Pillars by the other Guardians for her body allowed her to see her wrapped body and is why she retains its look.