I think you're supposed to shine the torches under your face, Tenryuu.
I believe she's trying to look all scary and like a ghost by strapping lights to the side of her head, although that is traditionally done with candles..
I'd honestly expect this kind of joke on Jintsuu, since historically she was shot at and sunk after shining her lights on enemy vessels.
It seems like the same happened to Tenryuu quite a bit as well; in fact, that was actually generally the case. I've seen plenty of remarks from American accounts saying that the Japanese were very effective with their searchlights. Specifically the tactic of using one "sacrificial" illuminator while the rest of the ships fired from darkness.
