Martial Master

The mural was treated as part of her Pranic Avatar's clothing. And, when she swapped places with her original self, the mural vanished from the scene. It didn't seem like a storage space like the one Re'Kha possessed.

But, only clothing or a substance full of Ghost Qi that was treated as part of the clothing or accessory work over the body. It ought to have been small objects. But, Ki'Nua had wrapped her Ghost Qi over the mural while infusing her will into it. And, since it too was an object full of Ghost Qi, she somehow made use of the advantages of her abilities to take it into her.

Moreover, Ki'Nua realised a certain fact at this point: Her ability to swap places with her Pranic Avatar and vice versa while also taking in the clothes or accessories she wore was her primary ability as a Sha. It was using this was she able to achieve it.