Bingo! Well spotted, Max!
Katy's slinky, skin-tight outfit is so reflective that you can see the reflection of a window, curtains and some items of furniture in it. Sometimes, if you look closely at the reflections in a model's eyes you can see fluorescent strip lights reflected in them. Like this close up of a tightly gagged Carlyelle.
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She was mummified lying on the floor, so her eyes are picking up the light coming from the ceiling.
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Hmmm... I'll bet she's quiet now, what with that extra layer of gagging tied over her taped up mouth and her nose!
Redjak.